Effect of Blocked Versus Random Practice on Physical Therapy Students' Manual Force Modulation

This study examined (a) the effect of practice organization on learning to modulate manual force, and (b) the effect of force magnitude on ability to accurately reproduce force. I randomly assigned 52 novice physical therapy students to either blocked or random practice schedules as they learned to apply different manual forces. I tested students immediately after training and one week later, using a three-way mixed design analysis of variance to assess the effects of practice organization (random vs. blocked), test (immediate posttest vs. retention test), and force (high vs. low) on ability to modulate manual forces. I found that blocked versus random practice, led to more accurate force application at the posttest and retention test, F(1, 50) = 5.57, p < .05; both practice groups performed more accurately at the posttest than at the retention test, F(1, 50) = 5.6, p < .05, and both performed more accurately at the lower, compared with the higher, force level, F(1, 50) = 60.9, p < .05. These findings support use of a blocked' practice schedule for this motor training, though relevant contextual interference moderators may include such variables as nature of the task, learners' skill levels, and practice time. In addition, higher forces resulted in greater errors and must be considered in preparing for and engaging in clinical practice.