High plantar flexor moment during the stance phase is known to cause high plantar pressure under the forefoot; however, the effects on plantar pressure due to a change of gastrocnemius medialis (GM) activity during gait, have not been investigated to date. Reciprocal inhibition is one of the effects of electrical stimulation (ES), and is the automatic antagonist alpha motor neuron inhibition which is evoked by excitation of the agonist muscle. The aim of this study was to investigate the influences of ES of the tibialis anterior (TA) on plantar pressure and the GM activity during gait in healthy adults. ES was applied to the TAs of twenty healthy male adults for 30 minutes at the level of intensity that causes a full range of dorsiflexion in the ankle (frequency; 50 Hz, on-time; 10 sec, off-time; 10 sec). Subjects walked 10 meters before and after ES, and we measured the peak plantar pressure (PP), pressure time integral (PTI), and gait parameters by using an F-scan system. The percentage of integrated electromyogram (%IEMG), active time, onset time, peak time, and cessation time of TA and GM were calculated. PP and PTI under the forefoot, rear foot, and total plantar surface significantly decreased after the application of ES. Meanwhile, changes of gait parameters were not observed. %IEMG and the active time of both muscles did not change; however, onset time and peak time of GM became significantly delayed. ES application to the TA delayed the timing of onset and peak in the GM, and caused the decrease of plantar pressure during gait. The present results suggest that ES to the TA could become a new method for the control of plantar pressure via modulation of GM activity during gait.

High plantar flexor moment and limited ankle mobility are known to cause high plantar pressure under the forefoot. Stretching is an effective physical therapy for the limited ankle range of motion (ROM), and electrical stimulation is used to regulate the activity of antagonistic muscle via the action of reciprocal inhibition. Additionally, stretching paired with electrical stimulation has been reported to improve the limited ROM significantly. This study aims to investigate the influences of stretching on triceps surae (STR), electrical stimulation to tibialis anterior (ES), and the combination (ES+STR) on the ROM, kinematic parameters, and plantar pressure distribution during gait in patients with diabetes mellitus. Planter pressure and other parameters were measured before and after the intervention of ES, STR, ES+STR, or the rest sitting on the bed (CON) for 10 min. Pressure time integral under the medial forefoot decreased in the ES+STR compared to CON ( P< .05). Interestingly, ES+STR increased passive and dynamic ROM on ankle dorsiflexion during gait and increased the lateral center of pressure excursion ( P < .05). Furthermore, these changes were followed by decreased contact duration under the medial forefoot ( P < .05). The combined therapy improves ankle mobility during gait and reduces the contact duration and the plantar pressure under the medial forefoot in patients with diabetes mellitus.

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High plantar pressure is a risk factor for diabetic foot ulcers, and it is known that restriction of ankle dorsiflexion range of motion (ROM) causes high plantar pressure. Stretching is a non-invasive and general means to improve ROM; however, the effect of stretching on the ROM and plantar pressure has not been clarified in patients with diabetes mellitus. We aimed to study the effects of intermittent weight-bearing stretching on ankle dorsiflexion ROM and plantar pressure during gait in patients with diabetes mellitus. Seven patients with diabetes mellitus participated, and their triceps surae was stretched using weight-bearing stretching with a stretch board. Five minutes of stretching was performed 4 times with a rest interval of 30 s. Ankle dorsiflexion ROM was measured with the knee flexed and extended. Peak pressure and pressure-time integral during gait were measured and calculated for the rearfoot, midfoot, forefoot, and total plantar surface before and after stretching. Ankle dorsiflexion ROM with the knee extended or bent increased significantly after stretching ( P < .05). Peak pressure and the pressure-time integral decreased significantly, especially in the forefoot ( P < .01), and these also decreased significantly in the total plantar surface ( P < .05). The duration of foot-flat decreased after stretching ( P < .05). Weight-bearing stretching improved ankle dorsiflexion ROM and reduced plantar pressure during gait. These results suggest that weight-bearing calf stretching may be an effective means to prevent and treat diabetic foot ulcers.