Date of Completion

5-6-2017

Embargo Period

4-27-2017

Advisors

Dr. Krystyna Gielo-Perczak, Dr. Patrick Kumavor, Dr. Heather Read

Field of Study

Biomedical Engineering

Degree

Master of Science

Open Access

Open Access

Abstract

Human vertical posture is an unstable system, requiring numerous mechanisms to maintain postural control. The ability to maintain upright stance without any assistance is a fundamental skill to be independently mobile. Plyometric exercises (such as jumping and hopping) are used by individuals involved in dynamic sports (athletes) to either enhance athletic performance or in rehabilitation of injured athletes to help them return to their sport as safe and as fast as possible. Short-term plyometric training has been shown to positively impact postural control and muscle power in athletes. There have been no studies which investigated this training in non-athletic individuals or considered postural stability changes as a result of this training. Positive changes in lower limb muscle power and therefore postural control, can be immensely beneficial to individuals recovering from injuries or individuals with impaired standing balance due to neurological disorders.

This study investigated a short-term (10 week), high intensity, bi-lateral plyometric training regime on young adults to observe, analyze and characterize their motor control and postural stability. This study involved ten healthy participants, who underwent the training three times a week, for ten weeks. Measurements were taken twice per session: (i) pre-exercise and (ii) post-exercise. Their center of pressure (CoP) recordings were carried out using a force plate, and their muscle activity was recorded using six electromyography (EMG) sensors placed on the right and left muscle bellies of the vastus lateralis (VL), biceps femoris (BF) and lateral gastrocnemius (GL). Participants were instructed to stand on the force plate for 90s, eyes open, shoulder width apart and hands by their sides. The exercise itself consisted of four sets of 30s maximal effort, bi-lateral jumps, with 60s rest in between. It was hypothesized that over time, there would be a reduction in the overall center of pressure (CoP) velocity, postural sway and 95% ellipse area. Our second aim was to determine the effect of this training on muscle activity in the lower limbs by evaluating vertical jump performance, EMG-EMG coherence of synergistic muscles, and gross innervation input of a select muscle for the task.

The results of this study indicate that plyometric training consisting of high impact bi-lateral exercises induced major improvements in lower extremity power and postural stability. There were significant changes in most CoP measures and EMG-EMG coherence. Therefore, we can conclude that short-term, high intensity plyometric training should be applied to impaired standing balance, and possibly included in rehabilitation programs to improve their mobility and quality of life.

Major Advisor

Dr. Krystyna Gielo-Perczak

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