The effect of trunk support on performance during arm ergometry in patients with cervical cord injuries

Earlier studies have shown that the diaphragm might have a postural function that could interfere with its respiratory function during arm cycling in patients with cervical cord injuries with impaired elbow extension. The purpose of this study was to evaluate the effect of trunk support on working performance in such patients. Ten patients with low-cervical-cord injuries performed an arm ergometer test without and with trunk support with at least one week between the tests. The work load averaged 30 (20-50) Watt. Oxygen uptake at steady state averaged 0.71 +/- 0.09 l/min without trunk support and 0.64 +/- 0.10 l/min with trunk support, P < 0.05. There was no difference in blood lactate without or with trunk support. Maximum performance time averaged 8.3 +/- 4.3 min without trunk support and 19.5 +/- 8.8 min with trunk support, P < 0.01. Oxygen saturation tended to decrease during work and returned to resting values after termination. This study showed that trunk support during arm ergometry in cervical-cord-injury patients with impaired elbow extension decreased the energy cost during sub-maximal work and increased the time to perform work. The results indicate that trunk stabilisation might improve performance of activities of daily living and that it should also be considered during exercise affecting the postural balance of these patients.