Model and Experimental Analyses of the Tricep Surae Strength Curve
Restricted (Penn State Only)
- Author:
- Marsh, Samuel
- Graduate Program:
- Kinesiology (MS)
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- August 07, 2023
- Committee Members:
- John Henry Challis, Thesis Advisor/Co-Advisor
Giampietro Luciano Vairo, Committee Member
Jonathan Dingwell, Professor in Charge/Director of Graduate Studies - Keywords:
- Muscle Model
Strength Curve
Tricep Surae
Muscle
Biarticular
Biodex - Abstract:
- Strength curves can provide useful information about how joint angle affects the maximum feasible isometric moment produced at a joint. Different muscle features can affect the shape of the strength curve and therefore at what joint angle the peak moment occurs. Collecting strength curve data can prove to be a long and arduous process due to many maximal isometric measurements being required of a participant. The purpose of this study, for the ankle plantarflexors, was to examine how varying muscle features effects the shape of the strength curve through theoretical analysis, and propose a better way to produce an isometric strength curve by using maximal isokinetic data. The rationale behind this study is that using maximal isokinetic data at low angular velocities would produce similar moments to that of maximal isometric data. Further, by using isokinetic data, this yields a more dense set of moments from a joint range of motion compared to isometric data. A muscle model was developed of the soleus and gastrocnemius muscles and used to estimate the ankle joint plantarflexion strength curves when three muscle features: tendon elasticity, force-length curve width, and the ratio of tendon to muscle fiber length were all varied. Simulations produced low velocity isokinetic strength curves which were the same in shape but different in magnitude to the isometric strength curve. Experimental work confirmed this relationship, after adjustment for scale differences there was no statistically significant difference between isometric and isokinetic strength measurements. These findings could prove to be useful in rehabilitation, and elite athlete training.