Effect of closed chain exercise on quadriceps femoris peak torque and functional performance

To determine the effect of a 6-week leg press training program on quadriceps femoris peak torque and lower extremity functional performance.

A 2 x 3 factorial design. A private university-based outpatient physical therapy clinic was used for testing. The university strength and conditioning center was used for training sessions.

A volunteer sample of thirty nonathletic, collegeage females participated. All thirty subjects completed the study.

Subjects were randomly assigned to either a control group (G(con)) or an exercise group that performed isotonic unilateral leg presses through either 0 to 60 degrees (G(60)) or 0 to 90 degrees (G(90)) of knee flexion. Subjects trained 3 days/wk for 6 weeks using the DAPRE technique. Pre and post isokinetic testing of the quadriceps femoris at 60 degrees /sec and hop tests for distance and time were measured.

Both training groups showed significant pre-post increases (p < .05) for: concentric peak torque, eccentric peak torque, and hop test for distance. G\(60) showed a significant decrease in hop test for time values. Significant increases (p < .05) in eccentric peak torque was seen between training groups and the control group, concentric peak torque was significantly greater only in G(90) as compared to G(con), on. No significant differences were observed between G(60) and G(90) for any of the measured variables. There were no differences between the three groups for any of the functional hop test measurements.

Unilateral leg press exercise performed through 0 to 90 degrees of knee flexion increases concentric and eccentric peak torque while training from 0 to 60 degrees improves eccentric torque. No changes in functional performance as measured by hop tests were seen in any groups. Transference between closed kinetic chain (CKC) exercise and open kinetic chain testing was supported, but not between CKC and functional performance testing.