Erika Zemková
Zuzana Kováčiková
Ludmila Zapletalová- 1Department of Biological and Medical Sciences, Faculty of Physical Education and Sports, Comenius University in Bratislava, Bratislava, Slovakia
- 2Sports Technology Institute, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Bratislava, Slovakia
- 3Institute of Physiotherapy, Balneology and Medical Rehabilitation, University of Ss. Cyril and Methodius in Trnava, Trnava, Slovakia
- 4Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czechia
The back is subjected to a great deal of strain in many sports. Up to 20% of all sports injuries involve an injury to the lower back or neck. Repetitive or high impact loads (e.g., running, gymnastics, skiing) and weight loading (e.g., weightlifting) affect the lower back. Rotation of the torso (e.g., golf, tennis) causes damage to both, the lumbar and thoracic spine. The cervical spine is most commonly injured in contact sports (e.g., boxing, football). One of the factors that increases the odds of injuries in athletes is excessive and rapid increases in training loads. In spite of currently emerging evidence on this issue, little is known about the balance between physiological loading on the spine and athletic performance, versus overloading and back pain and/or injury in athletes. This scoping review aims (i) to map the literature that addresses the association between the training load and the occurrence of back pain and/or injury, especially between the Acute:Chronic Workload Ratio (ACWR) and back problems in athletes of individual and team sports, and (ii) to identify gaps in existing literature and propose future research on this topic. A literature search of six electronic databases (i.e., MEDLINE, PubMed, Web of Science, SCOPUS, SportDiscus, and CINAHL) was conducted. A total of 48 research articles met the inclusion criteria. Findings identified that fatigue of the trunk muscles induced by excessive loading of the spine is one of the sources of back problems in athletes. In particular, high training volume and repetitive motions are responsible for the high prevalence rates. The most influential are biomechanical and physiological variations underlying the spine, though stress-related psychological factors should also be considered. However, limited evidence exists on the relationship between the ACWR and back pain or non-contact back injuries in athletes from individual and team sports. This may be due to insufficiently specified the acute and chronic time window that varies according to sport-specific schedule of competition and training. More research is therefore warranted to elucidate whether ACWR, among other factors, is able to identify workloads that could increase the risk of back problems in athletes.
Introduction
Back injuries and back pain are among the most common health problems in athletes affecting their performance (Trompeter et al., 2017). Acute injury or pain can be caused by falling, being tackled in team sports, fighting in combat sports, or while lifting heavy weights (Caine and Nassar, 2005; Aasa et al., 2017; Bromley et al., 2018; Plais et al., 2019). However, much more common than acute incidents are chronic back problems (Alzahrani et al., 2019). In many sports, the back and spinal column undergoes elevated stress for a long time (Lawrence et al., 2006). This may result in inflammation around the vertebrae and back muscles, which sometimes causes injuries to the discs but much more often leads to upper or lower back pain (Trompeter et al., 2017). Sciatica, for instance, is back pain that also affects the back of the legs or even the feet (Koes et al., 2007). It can occur in cyclists who are in a flexed forward posture or athletes of water and swing sports who perform a great deal of trunk rotation. Particularly in sports with repetitive asymmetric loading, the sacroiliac joint dysfunction is a frequent cause of low back pain in athletes (Peebles and Jonas, 2017). In most of these sports, asymmetric loading causes side-to-side dysbalances that may greatly enhance susceptibility to back pain. A clear example is an association between repeated golf swings and golf-related low back injuries (Cole and Grimshaw, 2016). Trunk rotational power represents the measure that reflects this asymmetric loading during trunk rotation (Zemková et al., 2019a). Its values were found to be significantly higher on the dominant than non-dominant side in golfers (∼15%), tennis (∼12%) and hockey players (∼14%) at lower or higher loads, whereas there were no significant between-side differences in a control group of physically active subjects (∼7%). This parameter is also able to reflect the specificity of training programs in the preparatory and competitive periods in canoeists, hockey and tennis players (Poór and Zemková, 2018). Similarly, wheelchair athletes, who suffer from spine curvature disorders, are at greater risk of back problems (Samuelsson et al., 2001). This is related to mainly those participating in sports that involve trunk rotational motions under loading and unloading conditions (Goosey-Tolfrey, 2010). A recent study demonstrated that wheelchair table tennis players exhibit lower mobility in the thoracic and lumbar regions of the spine during trunk flexion as well as lower lumbar inversion and pelvic retroversion than able-bodied athletes (Zemková et al., 2018b). Their limited range of motion (ROM) during trunk rotations and decreased posterior concavity contributes to lower trunk rotational velocity (Zemková et al., 2018b) and it may also increase the risk of spine injury. Velocity of trunk rotational movement is also compromised in older athletes, most likely due to their reduced ROM as a result of increased trunk stiffness with aging (Zemková et al., 2018a).
In spite of the fact that low back pain in athletes is among the most prevalent musculoskeletal condition with incidence rates of 1–30%, it is often neglected in research studies (Graw and Wiesel, 2008). The prevalence of low back pain is 1–94%, (the highest in rowing and cross-country skiing), and its point prevalence is 18–65% (the highest in rowing and the lowest in basketball) (Trompeter et al., 2017). Prevalence rates vary during an athlete’s season with the highest rates observed during the peak season (Newlands et al., 2015). The evidence on risk factors is mostly restricted to lumbar spine and hip flexibility, back muscle strength, trunk extensor/flexor endurance, and some anthropometric characteristics (Moradi et al., 2015; Trompeter et al., 2017). However, less attention has been paid to sport related factors. Among those, high training volume and repetitive motions contribute to the high prevalence rates (Fett et al., 2017). Athletes involved in impact sports are at risk for certain spinal pathologies that are associated with repetitive loading of the spine (Lawrence et al., 2006). For instance, higher incidence rates of spondylolysis and degenerative disk disease have been reported in elite athletes who participate in more intense training over a longer period of time than those who do not (Lawrence et al., 2006). Though muscle fatigue is often a symptom of back pain in athletes, factors like the number of training sessions per week only rarely have been investigated (Fett et al., 2017). The concept that compares the amount of acute workload performed in a 1-week relative to a 4-week chronic workload can provide useful information for designing the optimal workload that would improve athlete performance, and at the same time, decrease the likelihood of back pain and related injuries.
The Acute:Chronic Workload Ratio (ACWR) is a simplified version of the fitness-fatigue model that was first introduced by Banister et al. (1975). It is definied as the ratio between training loads in recent periods (∼5–10 days) and over longer periods (∼4–6 weeks) (Foster et al., 1999; Hulin et al., 2016b). The ACWR is calculated by using the rolling or exponentially weighted moving average model (Hunter, 1986). Though both models are used in practice, the first one is unable to deal with the decaying nature of fatigue and fitness effects over time and the non-linearity of workload and the occurrence of injury; thus it may less precisely reflect variations of accumulated loads (Williams et al., 2017; Menaspa, 2017). The second one, which attributes a decreasing weighting in order to compensate for the load latency effects (Williams et al., 2017), is more sensitive to detect increases in injury risk at higher ACWR ranges during the preseason and in-season periods (Griffin et al., 2020).
These models have been used to better control and understand the training process. Several studies have documented the association between the actual and modeled performance in a variety of individual sports (e.g., Taha and Thomas, 2003; Jobson et al., 2009) or injuries in team sports (e.g., Hulin et al., 2016a; Bowen et al., 2017; Murray et al., 2017). Contrary to this, less attention has been paid to the investigation and use of these models in association with the occurrence of injuries or pain that especially involve the spine and back muscles. So far the training volume, internal and external loads in different types of training, sport-specific demands on the spine in relation to back pain and/or injury have been primarily investigated (e.g., Maselli et al., 2015; Newlands et al., 2015; van Hilst et al., 2015). There is however, no sufficient evidence to determine the relationship between ACWR and the occurrence of back problems in athletes. A question also remains as to whether ACWR can be predictive of an athlete’s risk of back pain and/or injury.
To this end, two main questions were addressed in this scoping review: (1) Is the training load associated with the occurrence of back problems in athletes of individual and team sports? (2) Is there a relationship between the ACWR and back pain and/or injury in these athletes? Accordingly, this scoping review aimed at (i) mapping the literature that addresses the association between the training load and the occurrence of back pain and/or injury, especially between the ACWR and back problems in athletes of individual and team sports, and (ii) identifying gaps in existing literature and proposing future research on this topic.
Methods
The article was designed as a scoping review (Armstrong et al., 2011). In order to answer the above questions and to identify a gap in existing research in the field, a literature search was provided. Electronic literature was searched on MEDLINE, PubMed, Web of Science, SCOPUS, SportDiscus, and CINAHL databases. Further searches were conducted on Elsevier, SpringerLink, EBSCOhost, and Google Scholar. Besides articles in peer-reviewed journals, also conference proceedings were analyzed. The search was confined to studies closely associated with the major topic of this review, i.e., investigating the relationship between training loads and the occurrence of back problems in athletes, particularly between the ACWR and back pain and/or injury in athletes of individual and team sports. Our primary focus was concentrated on outcome measures of the ACWR and data related to back problems in athletes of individual and team sports. Using this approach, however, led to the identification of a limited number of studies that were able to meet the eligibility criteria for this review. Therefore the search was later widened to include all relevant studies that investigated the relationship between the training load and back pain and/or injury in athletes. Together these help us to identify gaps in the current literature regarding the training load, especially the ACWR and their associations with back pain and/or injury in athletes of individual and team sports, and suggest a proposal for future research.
The target population was athletes of individual (cricket, cycling, dancing, diving, golf, gymnastics, horseback riding, jiu jitsu, judo, powerlifting, rowing, running, skiing, swimming, triathlon, weightlifting, wrestling) and team sports (basketball, florball, handball, hockey, soccer, tennis, volleyball). The most frequent terms “Acute:Chronic Workload Ratio,” “back injuries,” “back pain,” “back problems,” “competition,” “external training load,” “fitness level,” “injury risk,” “internal training load,” “low back pain,” “neck/cervical pain,” “non-contact injury,” “thoracic pain,” and “training” were combined with particular individual and team sports. Additional searches were performed by using the words from subheadings, such as factors contributing to back pain and/or injury in athletes with respect to their localization, intensity, frequency, and duration. The key inclusion criterion was that studies involved athletes of individual and team sports with back pain and/or injury, a specified training program, and objective or subjective measures relevant to this review. Studies were excluded if they were incomplete (abstracts, etc.), not peer-reviewed, did not contain original research, and were not written in the English. Studies that failed to meet these criteria for this review were excluded. Figure 1 represents particular phases of the search process.
Figure 1. Flow chart illustrating phases of the literature search and study selection.
Results and Discussion
Overview of Studies Dealing With Back Pain and/or Injury in Athletes of Individual Sports
The key data elements that were sought for each study were categorized as follows: (1) study design, (2) study population (number of athletes, sex, age, type of sport, and performance level), (3) training characteristics, (4) low back pain information, (5) diagnostic methods used for identification of lumbar spine, low back pain and lower back injuries, and (6) study outcomes.
Out of the 31 research articles (Table 1), 21 studies (68%) included both sexes, six studies (19%) dealt with male athletes, and four studies (13%) focused on female athletes. A total of 2999 athletes of mean age of 26.1 years was evaluated, out of which 1819 were males and 1180 were females. Fifteen studies were conducted with elite athletes, nine studies assessed non-elite athletes, and six studies were conducted in both elite and non-elite athletes. For the purpose of this review, elite athletes were defined as those competing professionally at national level, international level or at the Olympic Games. Athletes competing at district and regional competition levels, as well as recreational and amateur athletes were defined as non-elite. Also athletes competing at high schools, colleges, or universities were considered as non-elite.
Table 1. Training characteristics and identified back problems in athletes of individual sports.
Regarding the individual sports, these groups of athletes were included: cricket bowlers (1 study), cyclists (5), dancers (2), divers (1), golfers (4), gymnasts (4), horseback riders (1), jiu jitsu athletes (1), judoists (1), powerlifters (1), rowers (2), runners (2), skiers (3), swimmers (2), triathletes (1), weightlifters (1), and wrestlers (1). Studies included athletes from the following countries: Australia (3 studies), Belgium (1), Brazil (1), Colorado (1), England (1), Germany (2), Greece (1), Italy (1), Japan (3), Korea (1), Poland (1), Spain (1), Sweden (5), Switzerland (1), and Zimbabwe (1). Country of origin was not specified in seven studies.
Lumbar spine abnormalities and alterations, low back injuries and pain were diagnosed in many different ways: using imaging systems such as magnetic resonance imaging (MRI), radiographs, CT, Spinal Mouse, motion analysis, ultrasonic measurements, through clinical examination, physical examination, various questionnaires, surveys, body charts, interviews, pain scales, and combinations of the above.
Overview of Studies Dealing With Back Pain and/or Injury in Athletes of Team Sports
Out of the 17 research articles (Table 2), seven studies (41%) included both sexes, six (35%) were focused on male and four (24%) on female athletes. The number of athletes in respective studies ranged from 29 to 1110 depending on the research methods used (retrospective vs. prospective). Ten out of these studies (56%) dealt with senior players, seven (39%) with junior players and one study (5%) with both age categories. Participants were top athletes (4 studies), elite players (4), non-elite players of different performance levels (5), and players of more than one performance level (5). Top athletes were considered those competing at the international level and taking part in top international competitions (Olympic Games, World Tours, and World Championships). Elite athletes were defined as the members of national teams not competing at the highest level or young athletes who were members of academies for talented youth. Non-elite athletes were from sport clubs, high schools, and colleges.
Table 2. Training characteristics and identified back problems in athletes of team sports.
Regarding the team sports category, the following groups of athletes were included: soccer players (7 studies), volleyball players (5), beach volleyball and handball players (3), field hockey, floorball, handball and basketball players (2), and the players of different types of rugby (1). Studies included were from the following countries: Norway (4 studies), Germany (3), United Kingdom, Sweden, and Finland (2), Switzerland, United States, Australia, Iran, and Portugal (1). Players included were from the same countries except of three studies which were conducted at major international events such as World Championships or World Tours.
This review includes two main types of studies: prospective cohort studies and retrospective studies. Low back injuries and pain or lumbar spine abnormalities were diagnosed in the following ways: using imaging systems (MRI), through physical examination by medical staff or physiotherapists, questionnaires, interviews, and their various combinations.
The Association of Workload With the Occurrence of Back Problems in Athletes of Individual and Team Sports
There is no conclusive evidence to date to demonstrate that the cause of low back pain in athletes of individual sports lies in undue abnormalities of the spine. Only one study (Koyama et al., 2013) confirmed lumbar disc degeneration as a statistically significant variable accounting for low back pain. However, no direct association between the training load and back injuries or abnormalities in the spine was confirmed. Nonetheless, there were trends toward an increased risk of injuries with increasing levels of performance and high physical loads.
Based on the MRI studies (Tertti et al., 1990; Baranto et al., 2006; Kaneoka et al., 2007; Kraft et al., 2009; Koyama et al., 2013; Sekine et al., 2014; Thoreson et al., 2017b; Witwit et al., 2018), the most common abnormalities in athletes of individual sports were as follows: reduced disc signal, degenerated discs at various disc levels, ring apophyses injury, disc bulging, Schmorl’s nodes causing severe back pain, abnormal configuration of the vertebra, and alterations in spinal curvatures.
In team sport games, the prevalence of overuse low back injuries accompanied by low back pain is rather high. However, the research findings are inconsistent. The level of prevalence depends on the type of research design used. While in prospective studies the prevalence of low back pain was evident in 9–20% of the cases (Bahr and Reeser, 2003; Jacobson and Tegner, 2007; Pasanen et al., 2008; Bere et al., 2015; Aasheim et al., 2018) or 2.25−0.4/1000 training and match hours (Bacon and Mauger, 2017; Bowen et al., 2017), in the retrospective studies it occurred in 15–97% of the cases depending on time to occurrence of back problems (point, 1-week, 1-, 3-, 12-month, life time prevalence) (Hoskins et al., 2009; Haydt et al., 2012; Külling et al., 2014; Leppänen et al., 2015; Tunås et al., 2015; Haag et al., 2016; Farahbakhsh et al., 2018; Fett et al., 2019).
The highest prevalence of low back pain was identified in field hockey, floorball, rugby, and beach volleyball (Nosco et al., 1999; Pasanen et al., 2008; Hoskins et al., 2009; Haydt et al., 2012; Külling et al., 2014; Fett et al., 2019). Among pain caused by overuse, low back pain was the most often reported pain with an incidence of 20–86% depending on the age category, sex, performance level, and the time of occurrence. In soccer, volleyball, and handball, low back pain was the third most common pain caused by overuse (Augustsson et al., 2006; Anza et al., 2013; Bere et al., 2015; Tunås et al., 2015; Bowen et al., 2017; Aasheim et al., 2018). In soccer, pain caused by overuse of groin and hip with a rate of 38–57% was the most common, followed by low back pain caused by overuse, whereas in volleyball and handball overuse injuries of shoulder and knee at a rate of 46–57% and 12–59%, respectively, were the most common, followed by low back pain.
The risk factors also include training and match load, which is characterized by the specific movement pattern of sport games, such as unilateral load, repetitive static flexion, hyperextension combined with rotation of the spine, jumps, impacts etc. (Snellman et al., 2001; Pasanen et al., 2008; Bere et al., 2015; Fett et al., 2019). However, the evidence is not unambiguous. The findings are mostly based on comparisons of athletes and non-athletes, and players with other athletes, top, elite, and non-elite players (Bahr and Reeser, 2003; Jacobson and Tegner, 2007; Hoskins et al., 2009; Anza et al., 2013; Bere et al., 2015; Haag et al., 2016; Aasheim et al., 2018).
In recent years, more attention has been directed toward objective quantification of training and match load, especially using the ACWR, and the examination of its relationship with injury risk (Griffin et al., 2020). Although 15 studies dealt with this issue in team sport games, only 2 of them can be included in this review (Bacon and Mauger, 2017; Bowen et al., 2017). In other studies, there was no distinction between the type and site of injuries.
Overall, the literature supports the association of training load with the occurrence of back problems in athletes of individual and team sports. A review by Moradi et al. (2015) identified many potential general and sport-specific risk factors for back pain in athletes, however, the evidence exists only for previous low back pain, decreased lumbar extension or flexion, and high body weight. Differences in the association between potential risk factors and back pain may be ascribed to the type of sport, level of competition, and training characteristics (Moradi et al., 2015). Evidently, properly designed training programs might not affect postural and core stability or increase the risk of injuries. For instance, lower lumbar lordosis and thoracic kyphosis, as well as anterior pelvic tilt while standing were identified in Latin American style professional dancers (Muyor et al., 2017). Though specific postures and movements in dance modify their spinal curvatures, it does not alter the spinal morphology in standing when compared to non-dancers. Further, Belavý et al. (2017) demonstrated that chronic running is associated with better intervertebral discs (IVD) composition and IVD hypertrophy. Generally, pain perception and processing is different in athletes as compared to normally active controls (Tesarz et al., 2012). This suggests a compensatory response of the endogenous antinociceptive system to the noxious input during exhaustive endurance training (Tesarz et al., 2013). More specifically, an overstressing of the endogenous pain inhibitory pathways may lead to exhaustion over time (Tesarz et al., 2013). This may result in disinhibition of pain processing when the acute pain is transmitted in the chronic pain and spatial pain spreading (Tesarz et al., 2013). On the contrary, the endogenous pain inhibitory pathways may be protected from chronic overstressing over time by a shift in the activation threshold, which may increase the efficiency of pain inhibition (Tesarz et al., 2013). Specific changes in pain thresholds and higher tolernce to pain at rest in athletes (Tesarz et al., 2012) has to be also taken into account when interpreting self-reported back pain and its relationship with physiological loading of the spine in athletes.
Actually, training is a protective factor against injury. As shown, high chronic workloads decrease the injury risk (Gabbett and Domrow, 2005). A lower risk of sustaining a subsequent injury was reported in athletes of team sports when they trained over 18 weeks before their initial injury (Gabbett and Domrow, 2005). A decreased risk of injury is also associated with well-developed physical qualities (Quarrie et al., 2001; Gabbett and Domrow, 2005; Gabbett et al., 2012; Gastin et al., 2015). Thus, progressively increased high training loads not only improve physical fitness of players but may also protect against injury (Gabbett, 2016). For instance, heavier rugby players with faster speed generate greater impact forces which may increase the recurrent rates of contact injuries (Gabbett et al., 2012). However, greater intermittent running speed at high intensity as well as muscle strength and power may decrease the risk of injuries in these players (Gabbett et al., 2012). This indicates that not only overtraining but also undertraining may increase the injury risk (Lyman et al., 2001; Orchard et al., 2009; Cross et al., 2016).
So far, the relationship between the ACWR and back pain/or injury in athletes remains unclear. This is mainly due to the limited evidence and varying methodological quality of particular studies. Nonetheless, it is most likely that sudden spikes in acute training loads may have detrimental effects, whereas high chronic loads and adequate strength and endurance of core muscles could provide protective effects on increasing the occurrence of back pain and/or injury. A structured back-strengthening program has been recommended for reduction of back pain experienced by athletes (Trainor and Wiesel, 2002). In practice, however, functional strength training for back pain prevention can be similar to programs for back pain rehabilitation (Wirth et al., 2017). Most exercises have not been tested for their effectiveness and compared with the load used for strength training. Neither are core strength exercises more effective than traditional resistance exercises (Smith et al., 2014) in individuals with back pain (Macedo et al., 2016; Saragiotto et al., 2016). Adaptations in voluntary activation of trunk muscles to core stability exercises have provided a basis for exercise guidelines (Wirth et al., 2017). However, adaptations of morphological structures that are essential for the core stability have not been sufficiently addressed in research studies. Therefore, the guidelines used for rehabilitation of back pain are insufficient for strength training in athletes (Wirth et al., 2017). Currently, there is no evidence-based exercise program for athletes with back pain and/or injury. Most studies investigated only a part with a narrow group of athletes who usually performed different types of exercise (Daniels et al., 2020). Recent evidence suggests that poor load management is a main injury risk factor (Soligard et al., 2016). Recently, the IOC provided the consensus statement that include guidelines for monitoring of training, competition and psychological load, prescription of training and competition load, athlete well-being and injury (Soligard et al., 2016).
Gaps in Current Studies Investigating the Workload in Relation to Back Problems in Athletes and Proposals for Future Research
One of the former studies reported that the incidence of injury is increased when the duration, intensity, and load of training sessions and matches in rugby league is increased (Gabbett, 2004a; Gabbett and Domrow, 2007). There is a U-shaped relationship for 4-week cumulative loads with an increase in injury risk with higher loads (Cross et al., 2016). The risk of injury in professional rugby union players increases if they have high 1-week cumulative loads or large week-to-week changes in the training load (Cross et al., 2016). Further, higher risk of injury is also associated with a large increase in acute workload in elite cricket fast bowlers (Hulin et al., 2014). A sharp increases in running workload, the ACWR > 2.0 for either total distance or a high-speed distance, increases the likelihood of injury in elite footballers in both a given and the subsequent week (Murray et al., 2017). Controlling for training load in a given week may decrease the odds of injury in the subsequent week. Windt et al. (2017) demonstrated that increasing participation in pre-season training may decrease the risk of in-season injury in elite rugby league players. Though increased amounts of high-velocity running are associated with higher risk of soft-tissue injury of the lower body, distances covered at moderate and low speeds are protective against this injury (Gabbett and Ullah, 2012). Decreasing the training load during an early-competition phase can reduce the odds of injury without compromising the agility performance in athletes of collision sports (Gabbett and Domrow, 2007). Likewise, reductions in pre-season training loads decrease training injury rates and at the same time increase the maximal aerobic power in rugby league players (Gabbett, 2004b). It seems that high chronic training loads may decrease the risk of injuries in athletes. For instance, elite rugby league players are more resistant to injury when train at a high than a low chronic workload with ACWRs 0.85–1.35, whereas they are less resistant to injury when ACWRs is ∼1.5 and they are subjected to“spikes” in acute workload (Hulin et al., 2016b). Very high and high chronic workloads have protective effects against match injury following shorter recovery periods between matches (Hulin et al., 2016a). Alternatively, a high aerobic capacity and playing experience protect injury in elite Gaelic football players against rapid changes in workload and high ACWRs > 2.0 (Malone et al., 2017a). Players better tolerated increased distances and exposures to maximal velocity when train at higher than at lower chronic loads (Malone et al., 2017b). Over- and under-exposure them to maximal velocity increased the injury risk (Malone et al., 2017b). Accordingly, high chronic workloads, combined with reductions in acute workloads before competition, decrease the risk of injury but might also improve sporting performance (Gabbett, 2016). In general, ACWRs ≥ 1.5 (i.e., greater acute than chronic training load) are associated with a higher injury risk than ACWRs in the range from 0.8 to 1.3. While most studies showed the association of Acute:Chronic markers with risk of injuries, its application in predictions of injuries is questioned (Fanchini et al., 2018; McCall et al., 2018). Rather, it can identify workloads that athletes should use to make a decision when risk of injury is increased or decreased (Hulin and Gabbett, 2019). Therefore, the ACWR should not be viewed in isolation.
Contrary to these studies, the suggested association between training loads and back pain and/or injury is based on case studies, expert opinions, and unpublished data, whereas some other findings are controversial. Analysis of the literature identified several limitations in relation to workloads and back problems in athletes. First, the studies that use the same methods are limited. Second, injury identification is often based only on players’ self-assessment. Third, the exposure hours are calculated as average values for training and playing, and in most cases are based on data reported by individuals. Additionally, prevalence of back pain and/or injury in some sports can be affected by sample size. Finally, numbers of injury definitions and time occurrence categories make a comparison among studies more difficult. Further studies using a wider methodological approach are necessary to deepen the knowledge and understanding the association between the training load, especially ACWR and back pain and/or injury in athletes of individual and team sports.
Because questionnaires are mainly used for identification of back pain, more objective methods evaluating spine curvature and flexibility (Muyor et al., 2017), strength, power and endurance of core muscles (Zemková et al., 2016a, 2017, 2019a,b; Zemková and Jeleň, 2019) and hamstrings (Zemková et al., 2015), as well as postural and core stability after perturbations (Zemková et al., 2016b) should be applied. In addition to sport-specific testing methods, basic physical fitness tests can be used (Zemková and Hamar, 2018). Athletes undergoing the high-level of training demonstrated similar deconditioning of the lumbar extensor muscles and used similar strategies to maintain spinal stability after unexpected perturbations to ensure the spine from pain and damage as compared to non-athletes with low back pain (Catalá et al., 2018). Assessment of training interventions for strengthening the core muscles is also necessary, not only in adult athletes with a predisposition to back pain and/or injury but also in adolescents (Zemková and Hamar, 2018). There is increasing evidence that an experience of back pain in 14-year-old individuals may be associated with pain in adulthood (Coenen et al., 2017). Repetitive flexion and extension loadings of young Functional Spinal Units causes MRI and histological changes in the growth zones and endplates that are most likely first signs of fatigue and an explanation for the spine injuries in adolescent athletes (Thoreson et al., 2017a). In spite of the fact that back pain and/or injury is one of the most prevalent diagnosis in athletes, the mechanism of back problems is poorly understood so far (Ball et al., 2019). Research studies conducted on athletes with back pain highlight physiological and biomechanical mechanisms as influential, whereas psychological factors are often neglected. Heidari et al. (2017) emphasizes the importance of mainly stress-related factors in prevention and rehabilitation of back pain. Therefore, more longitudinal studies are required in comparison with frequently conducted short-term experiments in order to investigate long-term changes in strength of core muscles and neuromuscular control of spine stability in athletes.
Collectivelly, the association between the ACWR and injury in a variety of sports has been well established. However, our review highlights the paucity of research studies directly evaluating the association between the ACWR and back pain and/or injury across a larger range of sports. The inconsistency in the methodology of calculating weekly training loads and missing specification of injuries are main limiting factors that restricted comparison between findings. To reduce the variability between studies, researchers need to clearly define the ACWR methodology and specify back problems. The acute and chronic time periods used for assessment of the ACWR may depend on the specific nature of particular sports. Future investigations would benefit from more information on the fundamentals of competition and training in particular sports, physical fitness attributes of athletes, and other back pain and/or injury risk factors.
Conclusion
Although the relationship exists between the training load and the occurrence of back problems in athletes of individual and team sports, this is not specifically related to ACWR. In comparison with biomechanical, physiological or stress-related psychological factors, sport-specific patterns underlying high prevalence rates are not fully elucidated. The fatigue of trunk muscles induced by excessive loading of the spine is one of the sources of back problems in athletes. Practitioners can address this issue by load management via the use of the ACWR. However, they should be aware that the acute and chronic time window may vary according to specific structure of individual and team sports and their training and competition schedules. Though this may provide important feedback on athlete’s workload, the questionable is the sensitivity and specificity of the ACWR to predict back problems. This is mainly due to the limited evidence on applications of this systems-model approach for identification of risk of back pain and back injuries. Future research should focus on investigation of ACWR validity in combination with multifaceted monitoring systems in prevention of back problems in athletes of both individual and team sports. Nonetheless, the ACWR can be used as an effective tool for monitoring the athlete’s responses to training thereby enable practitioners to design workloads that decrease the occurrence of back problems. It seems that high chronic workloads and adequate muscle strength and endurance have a protective effect on increasing the occurrence of sport-related injuries.
Data Availability Statement
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation, to any qualified researcher.
Author Contributions
All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.
Funding
This work was supported by the Cross-border Co-operation Programme INTERREG V-A SK-CZ/2018/06 (No. 304011P714) co-financed by the European Regional Development Fund, and the Slovak Research and Development Agency under the contract No. APVV-15-0704.
Conflict of Interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
Aasa, U., Svartholm, I., Andersson, F., and Berglund, L. (2017). Injuries among weightlifters and powerlifters: a systematic review. Br. J. Sports Med. 51, 211–219. doi: 10.1136/bjsports-2016-096037
Aasheim, C., Stavenes, H., Andersson, S. H., Engbretsen, L., and Clarsen, B. (2018). Prevalence and burden of overuse injuries in elite junior handball. BMJ Open Sport Exerc. Med. 4:e000391. doi: 10.1136/bmjsem-2018-000391
Adiele, D., and Morgan, G. P. (2018). Prevalence of musculoskeletal injuries in males and females practicing swimming from higher school of Zimbabwe. Am. J. Sports Sci. 6, 8–11. doi: 10.11648/j.ajss.20180601.12
Airaksinen, O., Brox, J. I., Cedraschi, C., Hildebrandt, J., Klaber-Moffett, J., Kovacs, F., et al. (2006). Chapter 4. European guidelines for the management of chronic nonspecific low back pain. Eur. Spine J. 15, S192–S300. doi: 10.1007/s00586-006-1072-1
Almeida, G. P. L., de Souza, V. L., Sano, S. S., Saccol, M. F., and Cohen, M. (2012). Comparison of hip rotation range of motion in judo athletes with and without history of low back pain. Man. Ther. 17, 231–235. doi: 10.1016/j.math.2012.01.004
Alricsson, M., Björklund, G., Cronholm, M., Olsson, O., Viklund, P., and Svantesson, U. (2016). Spinal alignment, mobility of the hip and thoracic spine and prevalence of low back pain in young elite cross-country skiers. J. Exerc. Rehab. 12, 21–28. doi: 10.12965/jer.150255
Alzahrani, H., Shirley, D., Cheng, S. W. M., Mackey, M., and Stamatakis, E. (2019). Physical activity and chronic back conditions: a population-based pooled study of 60,134 adults. J. Sport Health Sci. 8, 386–393. doi: 10.1016/j.jshs.2019.01.003
Angoules, A. G., Dionyssiotis, Y., Angoules, G. A., Balakatounis, K. C., Panou, A., and Papathanasiou, J. (2018). An epidemiological study of non-specific low back pain in non-professional female greek classic ballet dancers. Folia Med. 60, 248–253. doi: 10.1515/folmed-2017-0087
Anza, R., Denis, M., and Silva, M. F. (2013). Analysis of physical fitness, anthropometry and prevalence of musculoskeletal symptoms in the youth volleyball category. Rev. Bras. Med. Esporte 19, 62–65.
Armstrong, R., Hall, B. J., Doyle, J., and Waters, E. (2011). Cochrane update. ‘Scoping the scope’ of a cochrane review. J. Public Health (Oxf) 33, 147–150. doi: 10.1093/pubmed/fdr015
Augustsson, S. R., Augustsson, J., Thomee, R., and Svantesson, U. (2006). Injuries and preventive actions in elite Swedish volleyball. Scand. J. Med. Sci. Sports 16, 433–440. doi: 10.1111/j.1600-0838.2005.00517.x
Bacon, C. S., and Mauger, A. R. (2017). Prediction of overuse injuries in professional u18-u21 footballers using metrics of training distance and intensity. J. Strength Cond. Res. 31, 3067–3076. doi: 10.1519/JSC.0000000000001744
Bahr, R., and Reeser, J. C. (2003). Injuries among world-class professional beach volleyball players: the federation internationale de volleyball beach volleyball injury study. Am. J. Sports Med. 31, 119–125. doi: 10.1177/03635465030310010401
Ball, J. R., Harris, C. B., Lee, J., and Vives, M. J. (2019). Lumbar spine injuries in sports: review of the literature and current treatment recommendations. Sports Med. Open 5:26. doi: 10.1186/s40798-019-0199-7
Banister, E. W., Calvert, T. W., Savage, M. V., and Bach, T. (1975). A systems model of training for athletic performance. Austr. J. Sports Med. Exerc. Sci. 7, 57–61.
Baranto, A., Hellström, M., Nyman, R., Lundin, O., and Swärd, L. (2006). Back pain and degenerative abnormalities in the spine of young elite divers. Knee Surg. Sport Tr. A 14, 907–914. doi: 10.1007/s00167-005-0032-3
Belavý, D. L., Quittner, M. J., Ridgers, N., Ling, Y., Connell, D., and Rantalainen, T. (2017). Running exercise strengthens the intervertebral disc. Sci. Rep. 7:45975. doi: 10.1038/srep45975
Bere, T., Kruczynski, J., Veintimilla, N., Hamu, Y., and Bahr, R. (2015). Injury risk is low among world-class volleyball players: 4-year data from the FIVB injury surveillance system. Br. J. Sports Med. 49, 1132–1137. doi: 10.1136/bjsports-2015-094959
Bovens, A. M. P., Janssen, G. M. E., Vermeer, H. G. W., Hoeberigs, J. H., Janssen, M. P. E., and Verstappen, F. T. J. (1989). Occurrence of running injuries in adults following a supervised training program. Int. J. Sport Med. 10, 186–190. doi: 10.1055/s-2007-1024970
Bowen, L., Gross, A. S., Gimpel, M., and Li, F. X. (2017). Accumulated workloads and the acute:chronic workload ratio relate to injury risk in elite youth football players. Br. J. Sports Med. 51, 452–459. doi: 10.1136/bjsports-2015-095820
Bromley, S. J., Drew, M. K., Talpey, S., McIntosh, A. S., and Finch, C. F. (2018). A systematic review of prospective epidemiological research into injury and illness in Olympic combat sport. Br. J. Sports Med. 52, 8–16. doi: 10.1136/bjsports-2016-097313
Caine, D. J., and Nassar, L. (2005). Gymnastics injuries. Med. Sport Sci. 48, 18–58. doi: 10.1159/000084282
Catalá, M. M., Schroll, A., Laube, G., and Arampatzis, A. (2018). Muscle strength and neuromuscular control in low-back pain: elite athletes versus general population. Front. Neurosci. 12:436. doi: 10.3389/fnins.2018.00436
Coenen, P., Smith, A., Paananen, M., O’Sullivan, P., Beales, D., and Straker, L. (2017). Trajectories of low back pain from adolescence to young adulthood. Arthritis Care Res. 69, 403–412. doi: 10.1002/acr.22949
Cole, M. H., and Grimshaw, P. N. (2016). The biomechanics of the modern golf swing: implications for lower back injuries. Sports Med. 46, 339–351. doi: 10.1007/s40279-015-0429-1
Cross, M. J., Williams, S., Trewartha, G., Kemp, S. P., and Stokes, K. A. (2016). The influence of in-season training loads on injury risk in professional rugby union. Int. J. Sports Physiol. Perform. 11, 350–355. doi: 10.1123/ijspp.2015-0187
Daniels, J. M., Arguelles, C., Gleason, C., and Dixon, W. H. (2020). Back injuries. Prim. Care 47, 147–164. doi: 10.1016/j.pop.2019.10.008
Dennis, R. J., Finch, C. F., and Farhart, P. J. (2005). Is bowling workload a risk factor for injury to Australian junior cricket fast bowlers? Br. J. Sports Med. 39, 843–846. doi: 10.1136/bjsm.2005.018515
Ekstrand, J. (1982). Football Injuries and Their Prevention. Medical Dissertation No 130. Linköping: Linköping University.
Fanchini, M., Rampinini, E., Riggio, M., Coutts, A., Pecci, C., and McCall, A. (2018). Despite association, the acute:chronic work load ratio does not predict non-contact injury in elite footballers. Sci. Med. Football 2, 108–114. doi: 10.1080/24733938.2018.1429014
Farahbakhsh, F., Akbari-Fakhrabadi, M., Shariat, A., Cleland, J. A., Farahbakhsh, F., Seif-Bargh, T., et al. (2018). Neck pain and low back pain in relation to functional disability in different sport activities. J. Exerc. Rehabil. 14, 509–515. doi: 10.12965/jer.1836220.110
Fett, D., Trompeter, K., and Platen, P. (2017). Back pain in elite sports: a cross-sectional study on 1114 athletes. PLoS One 12:e0180130. doi: 10.1371/journal.pone.0180130
Fett, D., Trompeter, K., and Platen, P. (2019). Prevalence of back pain in a group of elite athletes exposed to repetitive overhead activity. PLoS One 14:e0210429. doi: 10.1371/journal.pone.0210429
Foster, C., Snyder, A., and Welsh, R. (1999). “Monitoring of training, warm up, and performance in athletes,” in Overload, Performance Incompetence and Regeneration in Sport, eds M. Lehmann, C. Foster, U. Gastmann, H. Keizer, and J. M. Steinacker (New York, NY: Kluwer Academic Plenum), 43–51. doi: 10.1007/978-0-585-34048-7_4
Gabbett, T. J. (2004a). Influence of training and match intensity on injuries in rugby league. J. Sports Sci. 22, 409–417. doi: 10.1080/02640410310001641638
Gabbett, T. J. (2004b). Reductions in pre-season training loads reduce training injury rates in rugby league players. Br. J. Sports Med. 38, 743–749. doi: 10.1136/bjsm.2003.008391
Gabbett, T. J. (2016). The training injury prevention paradox: should athletes be training smarter and harder? Br. J. Sports Med. 50, 273–280. doi: 10.1136/bjsports-2015-095788
Gabbett, T. J., and Domrow, N. (2005). Risk factors for injury in subelite rugby league players. Am. J. Sports Med. 33, 428–434. doi: 10.1177/0363546504268407
Gabbett, T. J., and Domrow, N. (2007). Relationships between training load, injury, and fitness in sub-elite collision sport athletes. J. Sports Sci. 25, 1507–1519. doi: 10.1080/02640410701215066
Gabbett, T. J., and Ullah, S. (2012). Relationship between running loads and soft-tissue injury in elite team sport athletes. J. Strength Cond. Res. 26, 953–960. doi: 10.1519/JSC.0b013e3182302023
Gabbett, T. J., Ullah, S., and Finch, C. F. (2012). Identifying risk factors for contact injury in professional rugby league players—application of a frailty model for recurrent injury. J. Sci. Med. Sport 15, 496–504. doi: 10.1016/j.jsams.2012.03.017
Gastin, P. B., Meyer, D., Huntsman, E., and Cook, J. (2015). Increase in injury risk with low body mass and aerobic-running fitness in elite Australian football. Int. J. Sports Physiol. Perform. 10, 458–463. doi: 10.1123/ijspp.2014-0257
Goldstein, J. D., Berger, P. E., Windler, G. E., and Jackson, D. W. (1991). Spine injuries in gymnasts and swimmers: an epidemiologic investigation. Am. J. Sports Med. 19, 463–468. doi: 10.1177/036354659101900507
Goosey-Tolfrey, V. (2010). Supporting the paralympic athlete: focus on wheeled sports. Disabil. Rehabil. 32, 2237–2243. doi: 10.3109/09638288.2010.491577
Graw, B. P., and Wiesel, S. W. (2008). Low back pain in the aging athlete. Sports Med. Arthrosc. Rev. 16, 39–46. doi: 10.1097/JSA.0b013e318163be67
Griffin, A., Kenny, I. C., Comyns, T. M., and Lyons, M. (2020). The association between the acute:chronic workload ratio and injury and its application in team sports: a systematic review. Sports Med. 50, 561–580. doi: 10.1007/s40279-019-01218-2
Haag, T. B., Mayer, H. M., Schneider, A. S., Rumpf, M. C., Handel, M., and Schneider, C. (2016). Risk assessment of back pain in youth soccer players. Res. Sports Med. 24, 395–406. doi: 10.1080/15438627.2016.1222275
Haydt, R., Pheasant, S., and Lawrence, K. (2012). The incidence of low back pain in NCAA Division III female field hockey players. Int. J. Sports Phys. Ther. 7, 296–305.
Heidari, J., Hasenbring, M., Kleinert, J., and Kellmann, M. (2017). Stress-related psychological factors for back pain among athletes: important topic with scarce evidence. Eur. J. Sport Sci. 17, 351–359. doi: 10.1080/17461391.2016.1252429
Hoskins, W., Pollard, H., Daff, C., Odell, A., Garbutt, P., Mchardy, A., et al. (2009). Low back pain status in elite and semi-elite Australian football codes: a cross-sectional survey of football (soccer), Australian rules, rugby league, rugby union and non-athletic controls. BMC Musculoskelet. Disord. 10:38. doi: 10.1186/1471-2474-12-158
Hulin, B. T., and Gabbett, T. J. (2019). Indeed association does not equal prediction: the never-ending search for the perfect acute:chronic workload ratio. Br. J. Sports Med. 53, 144–145. doi: 10.1136/bjsports-2018-099448
Hulin, B. T., Gabbett, T. J., Blanch, P., Chapman, P., Bailey, D., and Orchard, J. W. (2014). Spikes in acute workload are associated with increased injury risk in elite cricket fast bowlers. Br. J. Sports Med. 48, 708–712. doi: 10.1136/bjsports-2013-092524
Hulin, B. T., Gabbett, T. J., Caputi, P., Lawson, D. W., and Sampson, J. A. (2016a). Low chronic workload and the acute:chronic workload ratio are more predictive of injury than between-match recovery time: a two-season prospective cohort study in elite rugby league players. Br. J. Sports Med. 50, 1008–1012. doi: 10.1136/bjsports-2015-095364
Hulin, B. T., Gabbett, T. J., Lawson, D. W., Caputi, P., and Sampson, J. A. (2016b). The acute:chronic workload ratio predicts injury: high chronic workload may decrease injury risk in elite rugby league players. Br. J. Sports Med. 50, 231–236. doi: 10.1136/bjsports-2015-094817
Jacobson, I., and Tegner, Y. (2007). Injuries among Swedish female elite football players: a prospective population study. Scand. J. Med. Sci. Sports 17, 84–91. doi: 10.1111/j.1600-0838.2006.00524.x
Jobson, S. A., Passfield, L., Atkinson, G., Barton, G., and Scarf, P. (2009). The analysis and utilization of cycling training data. Sports Med. 39, 833–844. doi: 10.2165/11317840-000000000-00000
Joeng, H. S., Na, Y. M., Lee, S. Y., and Cho, Y. J. (2018). Injuries among Korean female professional golfers: a prospective study. J. Sports Sci. Med. 17, 492–500.
Jonasson, P., Halldin, K., Karlsson, J., Thoreson, O., Hvannberg, J., Swärd, L., et al. (2011). Prevalence of joint-related pain in the extremities and spine in five groups of top athletes. Knee Surg. Sport Tr. A. 19, 1540–1546. doi: 10.1007/s00167-011-1539-4
Junior, L. C. H., Costa, L. O. P., and Lopes, A. D. (2013). Previous injuries and some training characteristics predict running-related injuries in recreational runners: a prospective cohort study. J. Physiother. 59, 263–269. doi: 10.1016/S1836-9553(13)70203-0
Kaneoka, K., Shimizu, K., Hangai, M., Okuwaki, T., Mamizuka, N., Sakane, M., et al. (2007). Lumbar intervertebral disk degeneration in elite competitive swimmers: a case control study. Am. J. Sports Med. 8, 1341–1345. doi: 10.1177/0363546507300259
Koes, B. W., van Tulder, M. W., and Peul, W. C. (2007). Diagnosis and treatment of sciatica. BMJ 334, 1313–1317. doi: 10.1136/bmj.39223.428495.BE
Koyama, K., Nakazato, K., Min, S. K., Gushiken, K., Hatakeda, Y., Seo, K., et al. (2013). Radiological abnormalities and low back pain in gymnasts. Int. J. Sports Med. 34, 218–222. doi: 10.1055/s-0032-1316366
Kraft, C. N., Pennekamp, P. H., Becker, U., Young, M., Diedrich, O., Lüring, C., et al. (2009). Magnetic resonance imaging findings of the lumbar spine in elite horseback riders: correlations with back pain, body mass index, trunk/leg-length coefficient, and riding discipline. Am. J. Sports Med. 11, 2205–2213. doi: 10.1177/0363546509336927
Külling, F. A., Florianz, H., Reepschläger, B., Gasser, J., Jost, B., and Lajtai, G. (2014). High prevalence of disc degeneration and spondylolysis in the lumbar spine of professional beach volleyball players. Orthop. J. Sports Med. 2:2325967114528862. doi: 10.1177/2325967114528862
Lawrence, J. P., Greene, H. S., and Grauer, J. N. (2006). Back pain in athletes. J. Am. Acad. Orthop. 14, 726–735. doi: 10.5435/00124635-200612000-00004
Leppänen, M., Pasanen, K., Kujala, U. M., and Parkkari, J. (2015). Overuse injuries in youth basketball and floorball. Open Access J. Sports Med. 6, 173–179. doi: 10.2147/OAJSM.S82305
Lyman, S., Fleisig, G. S., Waterbor, J. W., Funkhouser, E. M., Pulley, L., Andrews, J. R., et al. (2001). Longitudinal study of elbow and shoulder pain in youth baseball pitchers. Med. Sci. Sports Exerc. 33, 1803–1810. doi: 10.1097/00005768-200111000-00002
Macedo, L. G., Saragiotto, B. T., Yamato, T. P., Costa, L. O. P., Menezes Costa, L. C., Ostelo, R. W. J. G., et al. (2016). Motor control exercise for acute non-specific low back pain. Cochrane Database Syst. Rev. 2:CD012085. doi: 10.1002/14651858.CD012085
Macera, C. A., Pate, R. R., Powell, K. E., Jackson, K. L., Kendrick, J. S., and Craven, T. E. (1989). Predicting lower-extremity injuries among habitual runners. Arch. Intern. Med. 149, 2565–2568. doi: 10.1001/archinte.149.11.2565
Malone, S., Roe, M., Doran, D. A., Gabbett, T. J., and Collins, K. D. (2017a). Aerobic fitness and playing experience protect against spikes in workload: the role of the acute:chronic workload ratio on injury risk in elite Gaelic football. Int. J. Sports Physiol. Perform. 12, 393–401. doi: 10.1123/ijspp.2016-0090
Malone, S., Roe, M., Doran, D., Gabbett, T. J., and Collins, K. (2017b). High chronic training loads and exposure to bouts of maximal velocity running reduce injury risk in Gaelic football. J. Sci. Med. Sport 20, 250–254. doi: 10.1016/j.jsams.2016.08.005
Maselli, F., Ciuro, A., Mastrosimone, R., Cannone, M., Nicoli, P., Signori, A., et al. (2015). Low back pain among Italian rowers: a cross-sectional survey. J. Back Muskuloskelet. 28, 365–376. doi: 10.3233/BMR-140529
McCall, A., Dupont, G., and Ekstrand, J. (2018). Internal workload and noncontact injury: a one-season study of five teams from the UEFA elite club injury study. Br. J. Sports Med. 52, 1517–1522. doi: 10.1136/bjsports-2017-098473
McHardy, A., Pollard, H., and Luo, K. (2007). One-year follow-up study on golf injuries in Australian amateur golfers. Am. J. Sports Med. 35, 1354–1360. doi: 10.1177/0363546507300188
Menaspa, P. (2017). Are rolling averages a good way to assess training load for injury prevention? Br. J. Sports Med. 51, 618–619. doi: 10.1136/bjsports-2016-096131
Moradi, V., Memari, A. H., ShayestehFar, M., and Kordi, R. (2015). Low back pain in athletes is associated with general and sport specific risk factors: a comprehensive review of longitudinal studies. Rehabil. Res. Pract. 2015:850184. doi: 10.1155/2015/850184
Murray, E., Birley, E., Twycross-Lewis, R., and Morrissey, D. (2009). The relationship between hip rotation range of movement and low back pain prevalence in amateur golfers: an observational study. Phys. Ther. Sport 10, 131–135. doi: 10.1016/j.ptsp.2009.08.002
Murray, N. B., Gabbett, T. J., Townshend, A. D., Hulin, B. T., and McLellan, C. P. (2017). Individual and combined effects of acute and chronic running loads on injury risk in elite Australian footballers. Scand. J. Med. Sci. Sports 27, 990–998. doi: 10.1111/sms.12719
Muyor, J. M., López-Miñarro, P. A., and Alacid, F. (2011). Spinal posture of thoracic and lumbar spine and pelvic tilt in highly trained cyclists. J. Sports Sci. Med. 10, 355–361.
Muyor, J. M., Zemková, E., and Chren, M. (2017). Effects of Latin style professional dance on the spinal posture and pelvic tilt. J. Back Musculoskelet. Rehabil. 30, 791–800. doi: 10.3233/BMR-150448
Newlands, C., Reid, D., and Parmar, P. (2015). The prevalence, incidence and severity of low back pain among international-level rowers. Br. J. Sports Med. 49, 951–956. doi: 10.1136/bjsports-2014-093889
Nosco, D. L., Kim Carpenter, D. C., and Zhang, J. (1999). Determination of risk factors for low back pain in female adolescent volleyball players. Int. J. Volleyball Res. 7, 33–42.
Orchard, J. W., James, T., Portus, M., Kountouris, A., and Dennis, R. (2009). Fast bowlers in cricket demonstrate up to 3- to 4-week delay between high workloads and increased risk of injury. Am. J. Sports Med. 37, 1186–1192. doi: 10.1177/0363546509332430
Pasanen, K., Parkkari, J., Kannus, P., Rossi, L., Palvanen, M., Natri, A., et al. (2008). Injury risk in female floorball: a prospective one-season follow-up. Scand. J. Med. Sci. Sports 18, 49–54. doi: 10.1111/j.1600-0838.2007.00640.x
Peebles, R., and Jonas, C. E. (2017). Sacroiliac joint dysfunction in the athlete: diagnosis and management. Curr. Sports Med. Rep. 16, 336–342. doi: 10.1249/JSR.0000000000000410
Piazza, M., Di Cagno, A., Cupisti, A., Panicucci, E., and Santoro, G. (2009). Prevalence of low back pain in former rhythmic gymnasts. J. Sports Med. Phys. Fitness 49, 297–300.
Piotrowska, S. E., Majchrzycki, M., Rogala, P., and Mazurek-Sitarz, M. (2017). Lower extremity and spine pain in cyclists. Ann. Agric. Environ. Med. 24, 654–658. doi: 10.5604/12321966.1233552
Plais, N., Salzmann, S. N., Shue, J., Sanchez, C. D., Urraza, F. J., and Girardi, F. P. (2019). Spine injuries in soccer. Curr. Sports Med. Rep. 18, 367–373. doi: 10.1249/JSR.0000000000000638
Poór, O., and Zemková, E. (2018). The effect of training in the preparatory and competitive periods on trunk rotational power in canoeists, ice-hockey players and tennis players. Sports (Basel) 6, E113. doi: 10.3390/sports6040113
Quarrie, K. L., Alsop, J. C., Waller, A. E., Bird, Y. N., Marshall, S. W., and Chalmers, D. J. (2001). The New Zealand rugby injury and performance project. VI. A prospective cohort study of risk factors for injury in rugby union football. Br. J. Sports Med. 35, 157–166. doi: 10.1136/bjsm.35.3.157
Reis, F. J., Dias, M. D., Newlands, F., Meziat-Filho, N., and Macedo, A. R. (2015). Chronic low back pain and disability in Brazilian jiu-jitsu athletes. Phys. Ther. Sport 16, 340–343. doi: 10.1016/j.ptsp.2015.02.005
Rostami, M., Ansari, M., Noormohammadpour, P., Mansournia, M. A., and Kordi, R. (2015). Ultrasound assessment of trunk muscles and back flexibility, strength and endurance in off-road cyclists with and without low back pain. J. Back Musculoskelet. Rehabil. 28, 635–644. doi: 10.3233/BMR-140559
Roussel, N., De Kooning, M., Schutt, A., Mottram, S., Truijen, S., Nijs, J., et al. (2013). Motor control and low back pain in dancers. Int. J. Sports Med. 34, 138–143. doi: 10.1055/s-0032-1321722
Ruckstuhl, L., and Clénin, G. (2019). Back pain and core strength in elite cycling. Schweiz Z. Med. Traumatol. 67, 44–48.
Samuelsson, K., Larsson, H., Thyberg, M., and Gerdle, B. (2001). Wheelchair seating intervention. Results from a client-centred approach. Disabil. Rehabil. 23, 677–682. doi: 10.1080/09638280110049900
Saraceni, N., Kemp-Smith, K., O’Sullivan, P., and Campbell, A. (2017). The relationship between lead hip rotation and low back pain in golfers – a pilot investigation. Int. J. Golf Sci. 6, 130–141. doi: 10.1123/ijgs.2017-0014
Saragiotto, B. T., Maher, C. G., Yamato, T. P., Costa, L. O. P., Menezes Costa, L. C., Ostelo, R. W. J. G., et al. (2016). Motor control exercise for chronic non-specific low-back pain. Cochrane Database Syst. Rev. 1, CD012004. doi: 10.1002/14651858.CD012004
Schultz, S. J., and Gordon, S. J. (2010). Recreational cyclists: the relationship between low back pain and training characteristics. Int. J. Exerc. Sci. 3, 79–85.
Sekine, C., Hirayama, K., Yanagisawa, O., Okubo, Y., Hangai, M., Imai, A., et al. (2014). Lumbar intervertebral disc degeneration in collegiate rowers. J. Phys. Fitness Sports Med. 3, 525–530. doi: 10.7600/jpfsm.3.525
Siewe, J., Rudat, J., Röllinghoff, M., Schlegel, U. J., Eysel, P., and Michael, J. P. (2011). Injuries and overuse syndromes in powerlifting. Int. J. Sports Med. 32, 703–711. doi: 10.1055/s-0031-1277207
Smith, B. E., Littlewood, C., and May, S. (2014). An update of stabilisation exercises for low back pain: a systematic review with meta-analysis. BMC Musculoskelet. Disord. 15:416. doi: 10.1186/1471-2474-15-416
Snellman, K., Parkkari, J., Kannus, P., Leppälä, J., Vuori, I., and Järvinen, M. (2001). Sports injuries in floorball: a prospective one-year follow-up study. Int. J. Sports Med. 22, 531–536. doi: 10.1055/s-2001-17609
Soligard, T., Schwellnus, M., Alonso, J. M., Bahr, R., Clarsen, B., Dijkstra, H. P., et al. (2016). How much is too much? (Part 1) international olympic committee consensus statement on load in sport and risk of injury. Br. J. Sports Med. 50, 1030–1041. doi: 10.1136/bjsports-2016-096581
Taha, T., and Thomas, S. G. (2003). Systems modelling of the relationship between training and performance. Sports Med. 33, 1061–1073. doi: 10.2165/00007256-200333140-00003
Tertti, M., Paajanen, H., Kujala, U. M., Alanen, A., Salmi, T. T., and Kormano, M. (1990). Disc degeneration in young gymnasts: a magnetic resonance imaging study. Am. J. Sports Med. 18, 206–208. doi: 10.1177/036354659001800216
Tesarz, J., Gerhardt, A., Schommer, K., Treede, R. D., and Eich, W. (2013). Alterations in endogenous pain modulation in endurance athletes: an experimental study using quantitative sensory testing and the cold-pressor task. Pain 154, 1022–1029. doi: 10.1016/j.pain.2013.03.014
Tesarz, J., Schuster, A. K., Hartmann, M., Gerhardt, A., and Eich, W. (2012). Pain perception in athletes compared to normally active controls: a systematic review with meta-analysis. Pain 153, 1253–1262. doi: 10.1016/j.pain.2012.03.005
Thoreson, O., Ekström, L., Hansson, H. A., Todd, C., Witwit, W., Aminoff, A. S., et al. (2017a). The effect of repetitive flexion and extension fatigue loading on the young porcine lumbar spine, a feasibility study of MRI and histological analyses. J. Exp. Orthop. 4:16. doi: 10.1186/s40634-017-0091-7
Thoreson, O., Kovac, P., Swärd, A., Agnvall, C., Todd, C., and Baranto, A. (2017b). Back pain and MRI changes in the thoraco-lumbar spine of young elite Mogul skiers. Scand. J. Med. Sci. Sports 27, 983–989. doi: 10.1111/sms.12710
Trainor, T. J., and Wiesel, S. W. (2002). Epidemiology of back pain in the athlete. Clin. Sports Med. 21, 93–103. doi: 10.1016/s0278-5919(03)00059-0
Trompeter, K., Fett, D., and Platen, P. (2017). Prevalence of back pain in sports: a systematic review of the literature. Sports Med. 47, 1183–1207. doi: 10.1007/s40279-016-0645-3
Trompeter, K., Fett, D., and Platen, P. (2019). Back pain in rowers: a cross-sectional study on prevalence, pain characteristics and risk factors. Sportverletz Sportschaden. 33, 51–59. doi: 10.1055/a-0648-8387
Tunås, P., Nilstad, A., and Myklebust, G. (2015). Low back pain in female elite football and handball players compared with an active control group. Knee Surg. Sports Traumatol. Arthrosc. 23, 2540–2547. doi: 10.1007/s00167-014-3069-3
van Hilst, J., Hilgersom, N. F., Kuilman, M. C., Kuijer, P. P. F. M., and Frings-Dresen, M. H. W. (2015). Low back pain in young elite field hockey players, football players and speed skaters: prevalence and risk factors. J. Back Musculoskelet. 28, 67–73. doi: 10.3233/BMR-140491
van Middelkoop, M., Kolkman, J., van Ochten, J., Bierma-Zeinstra, S. M. A., and Koes, B. W. (2007). Course and predicting factors of lower-extremity injuries after running a marathon. Clin. J. Sport Med. 17, 25–30. doi: 10.1097/JSM.0b013e3180305e4d
van Middelkoop, M., Kolkman, J., van Ochten, J., Bierma−Zeinstra, S. M. A., and Koes, B. W. (2008). Risk factors for lower extremity injuries among male marathon runners. Scand. J. Med. Sci. Sports 18, 691–697. doi: 10.1111/j.1600-0838.2007.00768.x
Villavicencio, A. T., Burneikienë, S., Hernández, T. D., and Thramann, J. (2006). Back and neck pain in triathletes. Neurosurg. Focus 21, 1–7. doi: 10.3171/foc.2006.21.4.8
Wilber, C. A., Holland, G. J., Madison, R. E., and Loy, S. F. (1995). An epidemiological analysis of overuse injuries among recreational cyclists. Int. J. Sport Med. 16, 201–206. doi: 10.1055/s-2007-972992
Williams, S., West, S., Cross, M. J., and Stokes, K. A. (2017). Better way to determine the acute:chronic workload ratio? Br. J. Sports Med. 51, 209–210. doi: 10.1136/bjsports-2016-096589
Windt, J., Gabbett, T. J., Ferris, D., and Khan, K. M. (2017). Training load–injury paradox: is greater preseason participation associated with lower in-season injury risk in elite rugby league players? Br. J. Sports Med. 51, 645–650. doi: 10.1136/bjsports-2016-095973
Wirth, K., Hartmann, H., Mickel, C., Szilvas, E., Keiner, M., and Sander, A. (2017). Core stability in athletes: a critical analysis of current guidelines. Sports Med. 47, 401–414. doi: 10.1007/s40279-016-0597-7
Witwit, W. A., Kovac, P., Sward, A., Agnvall, C., Todd, C., Thoreson, O., et al. (2018). Disc degeneration on MRI is more prevalent in young elite skiers compared to controls. Knee Surg. Sport Tr. A. 26, 325–332. doi: 10.1007/s00167-017-4545-3
Zemková, E., Cepková, A., Uvaček, M., and Hamar, D. (2016a). A new method to assess the power performance during a lifting task in young adults. Measurement 91, 460–467. doi: 10.1016/j.measurement.2016.05.077
Zemková, E., Cepková, A., Uvaček, M., and Šooš, L’ (2017). A novel method for assessing muscle power during the standing cable wood chop exercise. J. Strength Cond. Res. 31, 2246–2254. doi: 10.1519/JSC.0000000000001692
Zemková, E., and Hamar, D. (2018). Sport-specific assessment of the effectiveness of neuromuscular training in young athletes. Front. Physiol. 9:264. doi: 10.3389/fphys.2018.00264
Zemková, E., and Jeleň, M. (2019). Differentiation of the strength of back muscle contraction under fatigue: Does force feedback play a role? J. Sport Rehabil. doi: 10.1123/jsr.2018-0496 [Epub ahead of print].
Zemková, E., Jeleň, M., and Zapletalová, L. (2018a). Trunk rotational velocity in young and older adults: a role of trunk angular displacement. Res. Phys. Educ. Sport Health 7, 103–107.
Zemková, E., Miklovič, P., Dunajčík, A., and Hamar, D. (2015). Power as a parameter in the functional assessment of knee flexions and knee extensions on weight stack machines. Measurement 61, 141–149.
Zemková, E., Muyor, J. M., and Jeleň, M. (2018b). Association of trunk rotational velocity with spine mobility and curvatures in para table tennis players. Int. J. Sports Med. 39, 1055–1062. doi: 10.1055/a-0752-4224
Zemková, E., Poór, O., and Jeleň, M. (2019a). Between-side differences in trunk rotational power in athletes trained in asymmetric sports. J. Back Musculoskelet. Rehabil. 32, 529–537. doi: 10.3233/BMR-181131
Zemková, E., Poór, O., and Pecho, J. (2019b). Peak rate of force development and isometric maximum strength of back muscles are associated with power performance during load-lifting tasks. Am. J. Men’s Health 13, 1–8. doi: 10.1177/1557988319828622
Keywords: Acute:Chronic Workload Ratio, back problems, individual sports, team sports, training load
Citation: Zemková E, Kováčiková Z and Zapletalová L (2020) Is There a Relationship Between Workload and Occurrence of Back Pain and Back Injuries in Athletes? Front. Physiol. 11:894. doi: 10.3389/fphys.2020.00894
Received: 23 February 2020; Accepted: 02 July 2020;
Published: 24 July 2020.
Edited by:
Urs Granacher, University of Potsdam, GermanyReviewed by:
Beat Knechtle, University Hospital Zurich, SwitzerlandFrantisek Zahalka, Charles University, Czechia
Copyright © 2020 Zemková, Kováčiková and Zapletalová. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Erika Zemková, erika.zemkova@uniba.sk
†ORCID: Erika Zemková, orcid.org/0000-0003-0938-5691; Zuzana Kováčiková, orcid.org/0000-0002-9206-7725