Chapter 2 - Movement Analysis

• Fulcrum - the part of the lever system that pivots.
• Effort - the force applied to move the resistance or weight.
• Resistance (Load) - the load to be moved, usually involving weight/resistance.
• Fulcrum (triangle), effort (arrow) and resistance (square).
• First class lever - fulcrum in middle, movement of flexion and extension, high or low mechanical advantage.
• Example of a first class lever - the neck when raising your head to head a football. The neck muscles provide the effort, the neck is the fulcrum, and the weight of the head is the load.
• Second class lever - resistance in middle, movement is plantar flexion, high mechanical advantage.
• Example of a second class lever - the ankle area, taking off for a jump. When standing on tiptoe, the ball of the foot acts as the fulcrum, the weight of the body acts as the load and the effort comes from the contraction of the gastrocnemius muscle.
• Third class lever - effort is in the middle, movement is flexion, low mechanical advantage.
• Example of a third class lever - During a biceps curl, the fulcrum is the elbow joint, the effort comes from the biceps contracting and the resistance is the weight of the forearm and any weight that it may be holding.
• Load arm - distance from load to fulcrum.
• Effort arm - distance from effort to fulcrum.
• Mechanical advantage measures the efficiency of a lever. Calculated by effort arm/ resistance (load) arm.
• Sagittal Plane - runs vertically from front to back and divides the body into right and left parts, movements are flexion and extension (bicep curl, running), movement in this plane takes place about the TRANSVERSE AXIS.
• Frontal Plane - runs vertically from side to side and divides the body into anterior and posterior parts, movements are abduction and adduction (star jump, side lunge), movement in this plane takes place about the SAGITTAL AXIS.
• Transverse Plane - runs horizontally and divides the body into superior and inferior parts, movement is rotation (golf swing, wood-chop), movement in this plane takes place about the LONGITUDINAL AXIS.
• Sagittal Plane - Transverse axis, Frontal plane - Sagittal axis, Transverse Plane - Longitudinal axis
• Transverse Axis - runs horizontally from side to side and is perpendicular to the saggital plane. A front or back somersault takes place in the sagittal plane about the transverse axis.
• Sagittal Axis - runs horizontally from front to back and is perpendicular to the frontal plane. A cartwheel takes place in the frontal plane about the sagittal axis.
• Longitudinal Axis - runs verticallyand is perpendicular to the Transverse plane. A 360 degree spin in ice skating takes place in the transverse plane about the longitudinal axis.
• Planes - there are three imaginary planes that pass through the body to represent dynamic planes of movement.
• Axes - An axis is a straight line around which an object rotates. There are three axes of rotation.