Velocity-Based Training Induces Positive Muscle-Ultrasound Morphology Changes In Persons With Parkinson’s Disease

Velocity-based training (VBT) utilizes changes in velocity rather than load to dictate progressions. No study has examined the effects of VBT on changes in muscle structure in people with Parkinson’s disease (PD). PURPOSE: Changes in muscle thickness (MT), echo intensity (EI), fascicle angle (FA), and shear wave elastography (SWE) in the left and right rectus femoris (RF) and vastus lateralis (VL) muscles were analyzed following training that used 10% and 30% velocity threshold protocols. METHODS: MT, EI, and FA were measured using ImageJ software on images taken via B-mode ultrasound of the left and right RF and VL. SWE was measured in m/s. RESULTS: Mixed ANOVAs were used to detect main effects and interactions. Results are reported as mean difference (Mdiff) ± standard error (SE), 95% confidence interval, and p-values. Significant time effects were seen for MT in all muscle. Pairwise comparisons showed significant increases for the left RF (Mdiff ± SE = .204 ± .086; .020, .388, p = .033), right RF (Mdiff ± SE = .191 ± .053; .077, .305, p = .003), left VL (Mdiff ± SE = .188 ± .070; .037, .338, p = .018), and right VL (Mdiff ± SE = .139 ± .061; .009, .269; p = .038). For EI, significant time effects were seen for the right RF and left and right VL. Pairwise comparison showed significant decreases for the right RF (Mdiff ± SE = -3.37 ± 1.29; -6.129, .606, p = .020), left VL (Mdiff ± SE = -7.11 ± 2.68; -12.862, 1.362, p = .019), and right VL (Mdiff ± SE = -6.904 ± 2.106; -11.421, 2.388, p = .005). Group x time interactions were seen for EI of the left RF, right RF and right VL. Pairwise comparisons showed no difference between groups across time. For the right RF, there was a significant decline for the 30% group only (Mdiff ± SE = 6.489 ± 1.703, p = .029). The right VL pairwise comparison showed a significant improvement for the 30% group only (Mdiff ± SE = -13.059 ± 2.786, p = .011). There were significant time effects for FA in the right RF and SWE in the left RF. Pairwise comparisons showed a significant improvement for right RF for FA (Mdiff ± SE = -2.471 ± .844; .662, -4.281, p = .011), and in SWE for the left RF (Mdiff ± SE = -.292 ± .103; -.513, -.072, p = .013). CONCLUSION: Results indicate that VBT is an effective training modality for inducing positive changes in muscle morphology for individuals with PD. Further, a 30% velocity threshold is more effective than a 10% threshold.