Amplitude and stride-to-stride variability of muscle activity during Lokomat guided walking and treadmill walking in children with cerebral palsy.

BACKGROUND: The Lokomat is a commercially available exoskeleton for gait training in persons with cerebral palsy (CP). Because active contributions and variability over movement repetitions are determinants of training effectiveness, we studied muscle activity in children with CP, and determined (i) differences between treadmill and Lokomat walking, and (ii) the effects of Lokomat training parameters, on the amplitude and the stride-to-stride variability. METHODS: Ten children with CP (age 13.2 ± 2.9, GMFCS level II(n = 6)/III(n = 4)) walked on a treadmill (±1 km/h; 0% bodyweight support(BWS)), and in the Lokomat (50% and 100% guidance; ±1 km/h and ±2 km/h; 0% and 50% BWS). Activity was recorded from Gluteus Medius (GM), Vastus Lateralis (VL), Biceps Femoris (BF), Medial Gastrocnemius (MG) and Tibialis Anterior (TA) of the most affected side. The averaged amplitude per gait phase, and the second order coefficient of variation was used to determine the active contribution and stride-to-stride variability, respectively. RESULTS: Generally, the amplitude of activity was lower in the Lokomat than on the treadmill. During Lokomat walking, providing guidance and BWS resulted in slightly lower amplitudes whereas increased speed was associated with higher amplitudes. No significant differences in stride-to-stride variability were observed between Lokomat and treadmill walking, and in the Lokomat only speed (MG) and guidance (BF) affected variability. CONCLUSIONS: Lokomat walking reduces muscle activity in children with CP, whereas altering guidance or BWS generally does not affect amplitude. This urges additional measures to encourage active patient contributions, e.g. by increasing speed or through instruction.

Effectiveness and feasibility of eccentric and task-oriented strength training in individuals with stroke.

BACKGROUND: Strength training can increase function in individuals with stroke. However it is unclear which type of strength training is most effective and feasible. OBJECTIVE: To assess the effect and feasibility of an intervention combining eccentric and task-oriented strength training in individuals with chronic stroke. METHODS: Eleven participants were randomly assigned to a group first receiving four weeks of eccentric strength training and then four weeks of task-oriented strength training (EST-TOST) or vice versa (TOST-EST). Strength and upper limb function were administered with a hand-held dynamometer (HHD) and the Action Research Arm Test (ARAT) respectively. Feasibility was evaluated with the Intrinsic Motivation Inventory (IMI), the adherence and drop-out rate. RESULTS: Significant increases were found in ARAT score (mean difference 7.3; p < 0.05) and in shoulder and elbow strength (mean difference respectively 23.96 N; p < 0.001 and 27.41 N; p < 0.003). Participants rated both EST and TOST with 81% on the IMI, the adherence rate was high and there was one drop-out. CONCLUSION: The results of this study show that a combination of eccentric and task-oriented strength training is an effective and feasible training method to increase function and strength in individuals with chronic stroke.