Muscular activation changes in lower limbs after underwater gait training in Parkinson's disease: A surface emg pilot study

Background: Under water gait training (UT) has been proposed as an innovative rehabilitative strategy for the treatment of axial disorders in Parkinson Disease (PD) patients, in particular for balance and gait impairment. However, the basis for the improvement is unclear. Research question: The aim of this study was to evaluate improvements in the muscular activation in the lower limbs in a cohort of PD patients after UT. Methods: Ten PD participants in the “off” state and 10 controls (mean ± standard deviation of age and BMI were respectively: 71 ± 6 years, 28 ± 3 kg/m2; 65.5 ± 7 years, 28 ± 3 kg/m2) were enrolled in the study. After signing informed consent, they walked barefoot at their preferred speed on a 10 m walkway, before and after UT. The electrical activity of four muscles were collected bilaterally by means of a surface electromyography system (sEMG), two force plates and a motion capture system. All signals were synchronized in time with the gait cycle. The sEMG activity of Rectus Femoris (RF), Tibialis Anterior (TA), Biceps Femoris (BF) and Gastrocnemius Lateralis (GL) were acquired. The average from each signal was used to extract the peak of the Envelope (PoE) and its occurrence with respect to the gait cycle (PoPE%). Time and space parameters were determined. Results: Our results showed that UT in PD patients improved the muscle's recruitment pattern towards normal. The PD patients POPE% was comparable with the one of the controls (TA: 20–35 %, 75–80 % of gait cycle; GL: 0–15 %, 25–45 %, 85–100 % of gait cycle) after UT on each muscle with the exception of BF. The muscle co-activation plots failed to show improvement in line with the muscle activation. Significance: These results suggest that the muscle activation improvement with UT in PD participants might be due to a reorganisation at the executive rather than at the command level.