Muscle Mechanics Chapter 17 KINE 3301 Biomechanics of Human Movement
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- Slide 1
- Muscle Mechanics Chapter 17 KINE 3301 Biomechanics of Human
Movement
- Slide 2
- Instrumentation used to study muscle force- velocity and
force-length relationship.
- Slide 3
- Length changes to an individual sarcomere during an isometric
contraction. The sarcomere directly underneath the end-plate will
be the first to develop tension which causes the sarcomeres to the
right and left to lengthen.
- Slide 4
- Sarcomere Force Length Relationship
- Slide 5
- Force Length in Normal Joint Range of Motion
- Slide 6
- Force Velocity Relationship (P + a) V = b (Po P)
- Slide 7
- Efficiency of Eccentric & Concentric Exericse Bernard
Abbott, Brenda Bigland-Ritchie, JJ Woods Loiselle D S et al. J Appl
Physiol 2010;108:1465-1471 2010 by American Physiological
Society
- Slide 8
- DOMS Damage to Muscle Following Eccentric Contractions
- Slide 9
- Stretch Shorten Cycle 1.Stored elastic energy (tendon,
cross-bridge, and titin). 2.Eccentric phase elicits a stretch
reflex. 3.Eccentric phase pre-loads the muscle, so the concentric
phase begins at a higher force. 4.Two joint muscles (rectus
femoris, gastrocnemius) transfers energy and allows the muscle to
work at a lower velocity and a higher force. The stretch shorten
cycle is defined as an eccentric contraction followed by an
immediate concentric contraction. Additional work is performed
during the concentric phase of a stretch shorten cycle. This extra
work is attributed to:
- Slide 10
- Stretch Shorten Cycle The area under the force length curve is
equal to the work done.
- Slide 11
- Effects of Increasing the velocity of stretch on the concentric
work done for the concentric phase. 1974 by American Physiological
Society Adapted from: Cavagna and Citterio. J Appl Physiol 1974;
239:1-14.
- Slide 12
- Slide 13
- Three Component Muscle Model Describes the mechanical response
of muscle. Contractile Component (CC) models active cross-bridges.
Dashpot models muscle viscosity. Series Elastic Component (SEC)
models elastic structures in series (tendon, passive cross-
bridges, titin). The SEC explains extra work done in
stretch-shorten and EMD. Parallel Elastic Component (PEC) models
passive elastic structures (passive cross- bridges, connective
tissue: endomysium, perimysium, epimysium, titin, desmin.