Graduation Term
Spring 2025
Degree Name
Master of Science (MS)
Department
School of Kinesiology and Recreation
Committee Chair
Michael Torry
Committee Member
Marcel Lopes dos Santos
Committee Member
Samantha McDonald
Abstract
The purpose of this study was to describe the individual muscle forces and contributions to extensor force occurring during the propulsive phase of unloaded jumps in females and explore how these are influenced by increasing loads using the hex bar modality. Ten, college-aged females (height: 1.66 ± 0.09 m; weight: 68.63 ± 9.66 kg) with weightlifting experience performed hexagonal bar squat jumps at bodyweight (BW), BW+20% and BW+40% of 1RM. Traditional motion capture techniques were employed to collect dominate lower limb kinematics and kinetics. Individual muscle forces were estimated utilizing Static Optimization in OpenSim using a Gait2392 musculoskeletal model. Muscle forces across loaded conditions were evaluated utilizing RMANOVA for the gluteus maximus (GMAX), biceps femoris long head (BFLH), rectus femoris (RECF), vastus intermedius (VAST), medial gastrocnemius (GAST), and soleus (SOLE). Muscle contributions to net extensor force were calculated as timeseries and total contributions. For peak muscle forces, the RECF demonstrated differences from BW-BW+20% (p = 0.012) and BW-BW+40% (p = 0.004). Statistical Parametric Mapping (SPM) showed significant differences within the GMAX, BFLH, RECF, VAST, and SOLE timeseries muscle forces. Post hoc tests detected differences between BW-BW+20% and BW-BW+40% for the GMAX, BFLH, and RECF. The VAST was different between 20%-40%. The RECF showed differences in total contribution from BW-BW+20% (p = 0.003) and BW-BW+40% (p = 0.001). Timeseries muscle contributions of BFLH, RECF, and SOLE demonstrated differences in SPM. The effects of load on individual muscle forces and contributions is an important consideration when programming loaded jumps for athletic performance.
Access Type
Thesis-Open Access
Recommended Citation
Konkel, Jadon, "Lower Extremity Individual Muscle Forces in Females During Loaded Hex-Bar Squat Jumps" (2025). Theses and Dissertations. 2068.
https://ir.library.illinoisstate.edu/etd/2068