The objective of this study was to determine the duration of maintained calf muscle flexibility gained in young adults with calf muscle tightness, as measured by increases in ankle active and passive dorsiflexion range of motion (DFROM) after three stretching interventions. Twenty subjects (5 men and 15 women) with calf muscle tightness received the following three stretching interventions in one leg (assigned at random): static stretching (SS), eccentric training on stable surface (ETS), and eccentric training on unstable surfaces (ETU). The subjects received all three interventions to the same leg, applied in a random order. Each intervention had a break of at least 24 h in-between, in order to minimize any carryover effect. Each intervention used two types of stretching: with the calf muscle stretched and both knees straight, and with the knee slightly bent in order to maximize the activation of the soleus muscle. All three interventions were performed for 200 seconds. We measured the duration of maintained calf muscle flexibility through active and passive ankle DFROM before intervention, immediately after intervention (time 0), and then 3, 6, 9, 15, and 30 min after intervention. We found a difference in the duration of maintained calf muscle flexibility between the three interventions. In the ETS and ETU interventions, a significant improvement in calf muscle flexibility, both ankle active and passive dorsiflexion ranges of motion (ADFROM and PDFROM), was maintained for 30 min. In the SS intervention, however, ADFROM before 9 min and PDFROM before 6 min were statistically different from the baseline. Our results suggest that ETS and ETU may be more effective than SS for maintaining calfmuscle flexibility in young adults.

The purpose of this study was to determine the effectiveness of sit-to-stand training on unstable surfaces in individuals with stroke. Nineteen subjects with chronic stroke were divided into two groups: an experimental group (10 subjects) and a control group (9 subjects). They received 30 minutes of Neuro-developmental therapy (NDT) treatment, and sit-to-stand exercise for 15 minutes three times a week for four weeks. During the sit-to-stand training, the experimental group performed on an unstable AIREX balance pad, but the control group performed on a stable surface. Balance ability and weight-bearing distribution during quiet standing were measured before and after training period using the 7-item Berg balance scale-3P (BBS-3P) and the Five-times-sit-to-stand test (FTSST). In addition, the muscle strength of the knee extensor was evaluated before and after the training period. The results were as follows: 1) The weight-bearing distribution forward of the affected leg, increased significantly in the experimental group after the four-week intervention (p<.05), 2) The 7-item BBS-3P and FTSST increased significantly in the experimental group after the four-week intervention (p<.05), 3) The knee extensor muscle strength in both groups increased significantly after the four-week intervention (p<.05). In conclusion, the results of this study did not show that the sit-to-stand training on an unstable surface was more effective than on a stable surface. However, the results suggested that sit-to-stand training is effective in the balance training of stroke patients.