AUTHOR=Buehler Callum , Koller Willi , De Comtes Florentina , Kainz Hans 

TITLE=Quantifying Muscle Forces and Joint Loading During Hip Exercises Performed With and Without an Elastic Resistance Band

JOURNAL=Frontiers in Sports and Active Living

VOLUME=Volume 3 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2021.695383

DOI=10.3389/fspor.2021.695383

ISSN=2624-9367

ABSTRACT=An increase in hip joint contact forces (HJCF) is one of the main contributing mechanical causes of hip joint pathologies, such as hip osteoarthritis, and its progression. The strengthening of the surrounding muscles of the joint is a way to increase joint stability which results in a reduction of HJCF. Most exercise recommendations are based on expert-opinions instead of evidence-based facts. The aim of this study was to quantify muscle forces and joint loading during rehabilitative exercises using an elastic resistance band (ERB). Hip exercise movements of 16 healthy volunteers were recorded using a three-dimensional motion capture system and two force plates. All exercises were performed without and with an ERB and two execution velocities. Hip joint kinematics, kinetics, muscle forces and HJCF were calculated based on musculoskeletal simulations in OpenSim. Time-normalized waveforms of the different exercise modalities were compared with each other and with reference values found during walking. The results showed that training with an ERB increases both target muscle forces and HJCF. Furthermore, the ERB reduced the hip joint range-of-motion during the exercises. The type of ERB used (soft versus stiff ERB) and the execution velocity of the exercise had a minor impact on peak muscle forces and HJCF. The velocity of exercise execution, however, had an influence on the total required muscle force. Performing hip exercises without an ERB resulted in similar or lower peak HJCF and lower muscle forces than those found during walking. Adding an ERB during hip exercises increased peak muscle and HJCF but the values remained below those found during walking. Our workflow and findings can be used in conjunction with future studies in order to support exercise design.