EFFECT OF IMMOBILIZATION, IMMEDIATE MOBILIZATION, AND DELAYED MOBILIZATION ON THE RESISTANCE TO DIGITAL FLEXION USING A TENDON INJURY MODEL

This study employed a tendon injury model in chickens to determine the effect of immobilization, immediate mobilization, and delayed mobiliz ation on the energy required to fully flex the digit following surgica l trauma to the tendon, as determined by measurement of the work of fl exion (WOF). The immobilized group showed no increased WOF at 3 days c ompared to the zero time control values, followed by significant incre ased WOF at 1 week (36%), 2 weeks (41%), and 3 weeks (63%). The immedi ate mobilization tendons showed an initial 36% rise in the work of fle xion at 3 days, which increased to 40% at 1 week, and then decreased t o baseline control values by 3 weeks. Delaying the period of mobilizat ion until 5 days was not shown to significantly lower the peak WOF val ue at 1 week, but delaying the period of mobilization until 3 days low ered the peak WOF value at 1 week dramatically to 13%; both the 3- and 5-day delayed-mobilization groups returned to baseline WOF values by 3 weeks. From these data, it can be assumed that there is an early inc rease in the work necessary for flexion of the injured operated digit and tendon that is present in the immediately mobilized tendons at 3 d ays and persists to 1 week and that does not appear until 1 week in th e immobilized tendons; this rise in WOF can be blunted by delaying the institution of mobilization.