<p> The force-velocity and force-length relationships of
skeletal muscle have been thoroughly investigated in the
literature. Unfortunately many of the relationships that have
been applied to models of the human anatomy have been based
upon investigations that have been performed under in-vitro
conditions. It was the intention of this study to investigate
whether the relationships determined by in-vitro investigation
and assumed to be correct could accurately and properly be
applied to actual human examples. Previous investigation by
Leedham and Dowling (1991) displayed that when investigating
human elbow flexors and in particular the biceps brachii that
the force-length relationship did not concur with in-vitro
results. The purpose of this study was to investigate the
relationships between length, velocity, EMG and force of the
biceps muscle. </p> <p> Eight young adult males (22-26) were fastened into an
isoveloci ty device ( CYBEX) which allowed only flexion and
extension of the right elbow. The forearm was then rotated
eccentrically or concentrically through a range of motion from
50 to 170 degrees of extension (or vice-versa). The biceps
muscle was either maximally contracted voluntarily or was
excited using electrical stimulation at 40 Hz. Using the constant angle torque (CAT) method and three dimensional surfaces the force-velocity, force-length and EMG-velocity
relationships were investigated. <p> <p> The main conclusions of the study were that the neural
drive provided by electrical stimulation over the motor point
provided CMAPS of consistent amplitude regardless of the joint
angle or angular velocity. The concentric force-velocity
relationship of the biceps was in agreement with most accounts
in the literature however the eccentric contraction condition
displayed a peak force production at 30° Is then showed a
slight decline to plateau across faster eccentric velocities.
Increased eccentric force production was thought to be more
mechanical than neurological in nature. </p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22620 |
| Date | 09 1900 |
| Creators | Leedham, John |
| Contributors | Dowling, James, Human Biodynamics |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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