1.  Required readings:  Biomechanics and Motor Control of Human Movement (class text) by D.A. Winter, pp. 165-212

7. Microscopic-Macroscopic Structure of Skeletal Muscle

19. Motor Unit Twitch

20. Shape of Graded Contraction

30. Isometric Contraction

33. Muscle Model

41. Types of Muscle Contraction No mechanical work; physiological work Force of muscle contraction  resistance; series elastic component stretch = shortening of contractile element (few to 7% of resting length of muscle) Isometric Positive work; muscle moment and angular velocity of joint in same direction Force of muscle contraction = resistance; constant angular velocity; special case is isometric contraction Isokinetic Negative work; muscle moment and angular velocity of joint in opposite direction Force of muscle contraction  resistance Eccentric Positive work; muscle moment and angular velocity of joint in same direction Force of muscle contraction  resistance Concentric Work Definition Type of Contraction

50. 3-D Relationship of Force-Velocity-Length

51. 3-D Relationship of Force-Velocity-Length

53. Fusiform Fiber Arrangement Fa Fa = force of contraction of muscle fiber parallel to longitudinal axis of muscle  Fa = sum of all muscle fiber contractions parallel to long axis of muscle

55. Pennate Fiber Arrangement  Fm Fa Fa = force of contraction of muscle fiber parallel to longitudinal axis of muscle Fm = force of contraction of muscle fiber  = pennation angle Fa = (cos  )(Fm)  Fa = sum of all muscle fiber contractions parallel to long axis of muscle

60. Muscle Fiber Types Fast Intermediate Slow Rate of fatigue Large Intermediate Small Fiber diameter High Intermediate Low Glycogen content Low High High Myoglobin content Few Many Many Capillaries High Intermediate Low Glycolytic enzyme activity Anaerobic glycolysis Oxidative phosphorylation Oxidative phosphorylation Primary source of ATP production Fast Fast Slow Speed of contraction Type IIB Fast-Twitch Glycolytic (FG) Type IIA Fast-Twitch Oxidative-Glycolytic (FOG) Type I Slow-Twitch Oxidative (SO)