1	Chapter 3: The Biomechanics of Resistance Exercise
2	The Musculoskeletal System Axial Skeleton Head Vertebrae Ribes Sternum Sacrum
3	The Musculoskeletal System 2. Appendicular Skeleton Upper extremity Clavicle, scapula, humerus, carpals, metacarpals, phalanges Lower extremity Ilium, femur, tibia, fibula, tarsals, metatarsals, phalanges.
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5	Joints Fibrous joints: sutures of the skull Cartilagenous joints: intervertebral disks Synovial joints: elbow, knee Articulating surfaces covered with hyaline cartilage capsule secretes synovial fluid into joint
6	Joint axes of rotation Uniaxial joints: hinge joints like elbow Biaxial joints: ankle and wrist, thumb Triaxial (ball and socket) joints: glenohumeral, hip
7	Skeletal musculature Origin and insertion Proximal and distal Fleshy attachments Fibrous attachments Agonist Antagonist Synergist
8	"8." 8. Neutralizer 9. Stabilizer 10. Spurt muscle 11. Shunt muscle
9	Levers of the Musculoskeletal System Lever Fulcrum Moment arm Torque Muscle force Resistive force Mechanical advantage
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11	Classes of Levers
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15	Knee joint is not a true hinge
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20	Variations in Tendon Insertion
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22	Anatomical Reference System of the Body Anatomical Position Planes: Frontal Sagittal Transverse
23	Human Strength and Power Strength is the ability to exert force, but it can be measured in many different ways One repetition maximum Isometric maximum Maximum reps of a given weight Acceleration: change in velocity per unit of time Individual differences in ability to exert force at different speeds
24	"4." 4. Low speed or isometric lifting tests may not predict performance in sports that require high speeds through acceleration. 5. Better definition of strength: The maximal force that a muscle or muscle group can generate at a specified velocity 6. Power is a measurement of the ability to exert force at higher speeds. 7. Power is the time rate of doing work, where work is force times distance
25	"Work = Force X distance" Work = Force X distance Work Power = ------ Time
26	Units of measure Worldwide standard is SI units: Force is measured in Newtons (N) Distance in meters (m) Time in seconds (s) Work in joules (J) = 1 Nm Power in Watts (W) = 1 J/s
27	"Work done in lifting a..." Work done in lifting a weight is equal to the weight times the height lifted vertically, while the horizontal distance is not a factor. Example: Lift a 100 kg barbell 2 meters per repetition for 10 repetitions. The 100 kg is a mass. To determine its weight consider the equation F = ma, where the Force is the weight, and a is acceleration of gravity, 9.8 m/s²
28	"Weight = 100 kg X..." Weight = 100 kg X 9.8 m/s² Weight = 980 Newtons Work = 980 N X 2m X 10 reps = 19,600 J This method of calculating work is a more accurate way of determining volume of a strength workout. If it takes 40 s to perform this exercise: Power = 19,600 J/ 40 s = 490 W
29	Rotational work The work required to start an object rotating about an axis, or to change the velocity at which it rotates. The angle through which an object rotates is called its angular displacement, which is radians in the SI units; 1 radian = 57.3° Angular velocity is measured in radians/s Torque is expressed is expressed in Nm, different from work, however.
30	Rotational Work and Power Work = Torque X Angular displacement Power is work/time Power Lifting is not as powerful as other sports or Olympic lifting. Power = F x d = F x d = F x V t t
31	Force-Velocity relationship of muscle
32	Biomechanical Factors in Human Strength Neural Control Recruitment Rate coding Muscle cross-sectional area Fiber arrangement Pennate Angle of pennation
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34	"4." 4. Muscle length
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36	"5." 5. Joint angle
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40	"6." 6. Muscle contraction velocity 7. Joint angular velocity Concentric Eccentric Isometric 8. Strength to mass ratio
41	"9." 9. Body size Smaller athletes are stronger pound for pound than larger athletes. Classic formula: strength/body weight ^2/3
42	Sources of Resistance to Muscle contraction Gravity: Weight = m X g (F=ma) Applications to resistance training (figure 3.18)
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45	"b." b. In the squat, the positioning of the weight and the body weight influences the amount of torque about the hip and knees. 1. The forward lean of the lifter brings the weight closer to the knees, and is farther from the hip. 2. The hip extensors have more torque to produce than the knee extensors. 3. The Technique of lifting may shift weight so that the stronger joints do most of the work. 4. For the injured, weight can be shifted to reduce torque at the affected joint.
46	Weight Stack Machines Gravity is the source of resistance. Direction of the force is not necessarily straight down. By means of pulleys, cams, cables, and gears, machines have greater control of the direction of the exercise. Advantages of machines: safety, design flexibility, ease of use. Advantages of free weights: whole-body training, real-life activities Controversy: Nautilus.
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48	Inertia When a weight is accelerated it exerts an inertial force. The inertial force can act in any direction. Deceleration is a negative acceleration End of the repetition Slowing down an object
49	Friction Frictional Force = coefficienct of friction X normal force Used with belt of break pad cycle ergometers
50	Fluid Resistance
51	Elasticity
52	Electronically controlled devices
53	Negative Work and Power
54	Joint Biomechanics: Concerns in lifting The Back Back injury Intra-abdominal Pressure and lifting belts Valsalva maneuver The Shoulders The Knees Knee Wraps
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56	General Safety Tips Perform one or more warmup setswith relatively light weight, particularly for exercises that involve extensive use of the shoulder and knee. This stimulates blood flow to the muscles effecting the movement, increasing the temperature and pliability of the ligaments, tendons and other structures. Massage may provide additional benefit.
57	"2." 2. Perform basic exercises through full range of motion. Perform only specialized supplementary exercises through limited ROM. 3. Use relatively light weights when introducing new exercises or lifting after a layoff of two or more weeks. 4. Do not ignore pain in or around the joints. “Working through” pain can lead to chronic injury. Often, just reducing the weight and increasing the reps may be pain free, or by using different exercises. Sever pain and persistent may require a cessation of lifting temporarily of those exercises the aggravate the injury, but may continue on other exercises that do not.
58	"5.Never attempt maximal lifts without..." 5.Never attempt maximal lifts without proper preparation, which includes technique instruction and a minimum of several weeks of training. Phase in periods of maximal lifting a few times a year at most. 6. Postworkout icing of superficial joints under heavy stress may aid in prevention of injury and recuperation. 7. Inclusion of other exercises that use the same major muscle may promote joint stability and balance between opposing groups
59	"8." 8. Avoid bouncing at the bottom of a squat Take care when incorporating plyometrics into a program Do not attempt explosive exercises without qualified instruction and preparation.
60	Movement Analysis and Exercise Prescription Specificity- training is most effective when resistance exercises are similar to the sport activity Movement-oriented Exercise Prescription Motor patterns not normally trained: a. shoulder internal and external rotation (throwing, pulling) b. Knee flexion (sprinting) c. Hip flexion (kicking, sprinting)
61	"d." d. Ankle dorsiflexion (running) e. Hip internal and external rotation (pivoting)
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