A Study of the Intrinsic Muscle Properties of the Gastrocnemius in Ice Hockey Players
Open Access
- Author:
- Leonard, Cameron
- Area of Honors:
- Kinesiology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- John Henry Challis, Thesis Supervisor
Jonas Rubenson, Thesis Honors Advisor - Keywords:
- Force-Length Curve
Biomechanics
Skeletal muscle properties - Abstract:
- Muscle fibers have a force-length property which dictates the force a muscle can produce as a consequence of its length. How much of this curve that is expressed in vivo depends on the joint range of motion, the moment arm of the muscle, and the number of sarcomeres in series. The purpose of this study was to determine the expressed section of the force-length curve for the gastrocnemius in vivo for a specifically trained population. This study used participants from a Division I Women’s Ice Hockey Team. The rationale behind studying ice hockey players is that they perform most of their training at a constrained ankle angle due to the structure of the skate boot, which could affect the in vivo expression of the force-length curve of the gastrocnemius muscle. A muscle model was created of the major plantarflexion muscles and used to estimate plantarflexion moment-angle strength curves (isometric moment versus joint angle) for a variety of model parameters. These simulations predicted that a gastrocnemius with less sarcomeres in series would be more likely in vivo to operate on the plateau region of the force-length curve (expressed section). Due to the constraints imposed on the ankle joint of the skate it is hypothesized that the ice hockey players would be more likely to operate on the plateau of the force-length curve than non-specifically trained subjects. The in vivo expressed section of the force-length curve of the gastrocnemius was determined for twelve subjects by collecting isometric moment joint angle data and exploiting the fact that the gastrocnemius crosses both the ankle and knee joints. The study found that more of the ice hockey players operated over the plateau region of the force-length curve compared with an untrained group who mostly operated on the ascending limb (p<0.0001). These findings suggest that prolonged training with the ankle motion constrained could cause changes in the number of sarcomeres in series producing an adaptive change in the in vivo expressed section of the force-length curve.