Effects of 10 weeks of oscillation stretching training on gastrocnemius medialis muscle-tendon behaviour and walking energetics in people with type 2 diabetes

Background: We evaluated the possible differences between healthy individuals and subjects with well-controlled type 2 diabetes (T2D) in the energetics and muscle-tendon behaviour of walking. Moreover, we investigated the effects of a 10-week oscillatory-stretching (MOS) training protocol on the plantarflexor muscles in T2D patients. Research question: How do muscle-tendon mechanics and walking energetics differ between healthy adults and T2D patients, and how does a 10-week MOS training protocol affect plantarflexor function in T2D patients? Results: Fourteen T2D patients and thirteen healthy controls performed a single walking trial at 4 km/h while kinematics parameters (i.e., stride length, frequency and ankle range-of-motion (ROM)), the gastrocnemius medialis (GM) muscle-tendon behaviour, and the net energy cost of walking (Cnet) were evaluated. T2D patients performed these experiments twice: pre- and post-10 weeks of MOS training (7 training sessions per week). At baseline, no significant differences were observed between populations in stride length, stride frequency, GM fascicle behaviour, and Cnet. However, T2D patients exhibited lower ankle ROM and shorter SEE elongation. These parameters were recovered after training, with no further differences when compared to healthy people. Significance: Well-controlled type 2 diabetes affects the SEE behaviour and the ankle ROM during walking at a velocity close to the "optimal" one. Moreover, we observed that 10 weeks of MOS training are effective in increasing SEE elongation during the stance phase, as well as ankle ROM, in diabetic patients. These findings suggest that this simple training protocol could be useful to mitigate mechanical SEE deterioration in T2D patients.