DISCUSSION
Our major finding was that statistically significant kneeextension range-of-motion gains of 6.80 and 5.60 were maintained at 1 and 3 minutes poststretching, respectively. The range-of-motion gains returned to the baseline by 6 minutes after stretching. The inability to maintain significant knee-extension angles beyond 3 minutes in our study suggests that a temporary creep effect occurred in which the viscoelastic component of the hamstrings was not deformed enough to produce a permanent change. With respect to the contractile component of muscle, Bohannon proposed that the inability of the hip joint to maintain significant flexion angles after hamstring stretching was due to temporary sarcomere lengthening. Temporary sarcomere lengthening may have occurred with our hamstring stretch subjects. Bohannon recorded 1 of 2 follow-up measurements in an elapsed time frame similar to that incorporated in our study. Over the course of 3 consecutive days of 8-minute passive loading, Bohannon recorded statistically significant (P < .01) maintained angles of hip flexion of 3.00 (day 1), 3.30 (day 2), and 2.90 (day 3) at 10 minutes postloading. Ten minutes after cessation of an 8-minute static stretch, Bohannon recorded a statistically significant (P < .01) maintained angle of hip flexion of 3.00. The return of knee extension in our study to baseline at 6 minutes is similar to the inability of the hip joint in Bohannon's study to maintain any significant increase 10 minutes after cessation of the stretch. Although the 2 studies differed in procedure, the results suggest that the hamstring complex (including the hip and knee joints) may require greater durations of stretch or increased stretching repetitions in order to create more permanent changes in its contractile and noncontractile components. The ability of the stretching protocol to increase the angle of knee extension 6.80 (at 1 minute) was slightly less than the 8.00 and 9.20 reported by Worrell et al, and Sullivan et al, respectively. However, our study reported similar results with fewer stretches. All 3 studies incorporated a prebaseline warm-up, used the AKE test to measure knee joint range of motion, and had subjects perform a static stretching protocol in an upright position. The differences in the angle of knee extension at 1 minute recorded by Worrell et al and Sullivan et al may be the result of the number of stretches: 48 total stretches (15 stretching sessions performed over a 3-week