Individual Muscle Force Differences During Loaded Hexbar Jumps: A Statistical Parametric Mapping Analysis

• Published in: Annals of biomedical engineering Vol. 51; no. 9; pp. 1975 - 1983
• Main Authors: Salvadore, Abigail K., Jagodinsky, Adam E., Torry, Michael R.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2023; Springer Nature B.V
• Subjects: Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Classical Mechanics; Electromyography; Exercise - physiology; Force; Hamstring Muscles - physiology; Humans; In vivo methods and tests; Male; Mapping; Motion capture; Muscle, Skeletal - physiology; Muscles; Optimization; Original Article; Peak values; Quadriceps Muscle - physiology; Statistics; Training; Biomechanics; Weightlifting; Musculoskeletal modeling
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1007/s10439-023-03218-w

Knowledge of individual muscle force during strength and conditioning exercises provides deeper understanding of how specific training decisions relate to desired training outcomes. The purpose of this study was to estimate individual muscle forces during hexbar jumps with 0%, 20%, 40%, and 60% of the hexbar deadlift 1-repetition maximum utilizing in vivo motion capture and computational modeling techniques of male participants. Muscle forces for the gluteus maximus, biceps femoris, rectus femoris, vastus intermedius, gastrocnemius, and soleus were estimated via static optimization. Changes in muscle forces over the concentric phase were analyzed across loading conditions using statistical parametric mapping, impulse, and peak values. Conclusions about the effects of load differ between the three analysis methods; therefore, careful selection of analysis method is essential. Peaks may be inadequate in assessing differences in muscle force during dynamic movements. If SPM, assessing point-by-point differences, is combined with impulse, where time of force application is considered, both timepoint and overall loading can be analyzed. The response of individual muscle forces to increases in external load, as assessed by impulse and SPM, includes increased total muscle output, proportionally highest at 20%1RM, and increased absolute force for the vasti and plantarflexors during the concentric phase of hexbar jumps.