Velocity-based And Traditional Strength Training Impact Muscle Morphology And Performance In Persons With Parkinson’s Disease

PURPOSE: To examine the comparative changes in muscle structure and performance of PD patients following VBT and TST. METHODS: 19 PD patients (73.1 ± 6.7 y) were randomly assigned to the VBT or TST group. Exercises were performed on computerized pneumatic resistance machines (HUR USA, Northbrook, IL) two days/week for 8 weeks. Ultrasound, power and strength were assessed before and after training. RESULTS: Separate 2 x 2 x 2 (group x time x leg) repeated measures ANOVAs revealed significant main effects for time for rectus femoris (RF) MT (F (1,17) = 20.948, p < .001, np2 = .552) and vastus lateralis (VL) MT (F (1,17) = 22.304, p < .001, np2 = .567). Pairwise comparisons showed significant improvements in MT across time in both legs for the RF (MDiff ± SE = .31 ± .07 cm, p < .001) and the VL (.27 ± .06 cm, p < .001). For MQ there was a main effect for time for VL (F (1,17) = 13.553, p = .002, np2 = .444) with pairwise comparisons revealing reductions (improvements) in MQ (-18.7 ± 5.1, p = .002). A main effect for time was seen for MS of the VL (F (1,17) = 5.191, p = .038, np2 = .230) with pairwise comparisons showing a reduction over time (-4.9 ± 2.2, p = .038). Separate 2 x 2 repeated measures ANOVAs revealed a main effect for time for leg press (LP) 1RM (F (1,17) =26.597, p < .001, ηp2 = .610) and LP-PP across percent loads (F (1,17) = 5.597, p = .030, ηp2 = .139). Pairwise comparisons revealed a significant increase in LP1RM (16.6 ± 3.2 kg; p < .001) and LP-PP at 60% (98.9 ± 35.2 W; p = .012), 70% (82.8 ± 37.5 W; p = .041) and 80% 1RM (91.5 ± 38.9 W; p = .031) specific to the VBT condition. CONCLUSIONS: Both VBT and TST are effective training strategies in PD persons for improving lower-limb MT and quality, irrespective of their affected side. Further, VBT elicits greater improvements in maximal power compared to TST.