PPT Slide
Example 1: Bicep Curl: Flexion and Extension at the Elbow Joint.
The displacement at the elbow joint starts at anatomical zero and travels through
Flexion (Phases 1 & 2 on figure) and Extension (Phases 3 & 4 on figure).
The velocity of the movement is graphed on the figure. There is an ? in the flexion velocity at the beginning of the movement (Phase 1; the velocity ? in the flexion direction) at mid-flexion range the velocity ? back towards zero as the flexion directed movement begins to slow down (Phase 2).
During the extension phase, the velocity ? during the extension directed movement (Phase 3) and then ? towards zero as the movement ends (Phase 4).
The acceleration at this point of the motion is maximized to initiate movement into the flexion direction (Start of Phase 1). As we reach the midpoint of the flexion movement, flexion velocity peaks and acceleration drops to “0”(The transition point between Phases 1 & 2). At the point of maximum flexion, velocity drops to “0” and acceleration is again maximized to initiate movement into the extension direction (The transition point between Phases 2 & 3). Movement now reverses and continues into the extension direction with an ? in velocity resulting from an ? acceleration into extension (Phase 3). As we reach the midpoint of the extension movement, extension velocity peaks and acceleration drops to “0”(The transition point between Phases 3 & 4). Finally, as we near the end of the extension movement, velocity returns back toward “0” (Phase 4).
Go through similar steps with the “shuttle run” as an example.
The shuttle run is when athletes run across the basketball court
in one direction and then return to the starting position.