Presentation on theme: "Center of Mass Chapter 12 KINE 3301 Biomechanics of Human Movement."— Presentation transcript:
Center of Mass Chapter 12 KINE 3301 Biomechanics of Human Movement
Segmental Method for Computing Center of Mass SegmentSegment Weight (N)CM Location (%) Proximal End Head0.032 x BW Top of Head Trunk0.532 x BW – ST Cervical Upper Arm0.022 x BW Shoulder Forearm0.013 x BW Elbow Hand0.005 x BW Wrist Thigh0.127 x BW – Hip Lower Leg0.044 x BW – Knee Foot0.009 x BW Ankle From: Chandler, R. F., C. E. Clauser, et al. (1975).
Computing the Location of a Segments CM
How to Use Segmental Method 1.Determine the X, Y location of the endpoints of all body segments. 2.Determine the weight of each segment. 3.Determine the location of each segments center of mass. 4.Multiply the segment weights by the x or y coordinates and then divide by the total weight to determine the location of the body center of mass.
Using Excel to Compute CM
Sagittal View Example SegmentSegment Weight (N)CM Location (%) Proximal End Head0.032 x BW Top of Head Trunk0.532 x BW – ST Cervical Thigh0.127 x BW – Hip In the back handspring assignment we are assuming that the right and left limbs move symmetrically, so the weights must be doubled, in cell F5 enter the following: =2*((0.127*$L$2)-14.82)