International survey of osteoporosis in Asia (ISOPA)

volume of each muscle was then calculated. Results: Countermeasure intervention reduced or prevented atrophy in medial gastrocnemius, soleus, lateral gastrocnemius and vastii muscles (F>3.0, p≤ .0247). Atrophy of the peroneals, tibialis posterior, and flexor digitorum longus was also less in the countermeasure group, though statistical evidence for this was weak (F≤2.3, p≥ .071). The countermeasure did not prevent atrophy in the hamstring muscles (F .38). The adductor longus, sartiorius and rectus femoris muscles showed little loss of muscle volume during bed-rest (F .088). Conclusion: The countermeasure exercise programme was effective in reducing muscle atrophy in the extensors of the knee and ankle. Future work needs to consider optimising exercises to be as time efficient as possible in targeting the muscles most affected in bed-rest/spaceflight.