Objective: We investigated the effects of the incremental arm-cranking exercise (ACE) on tissue oxygen saturation (StO₂) between active and inactive muscles, and the relationship between peak oxygen uptake (VO_2peak) and changes in the StO₂ in inactive muscles.

Design: Observational study.

Setting: Community-based supervised intervention.

Participants: The participants were individuals with motor and sensory complete spinal cord injury (complete SCI; n = 8) and motor complete but sensory incomplete SCI (incomplete SCI; n = 8), and able-bodied (AB) individuals (n = 8) matched for age, height, and body mass index.

Intervention: The ACE was performed at a rate increasing by 10 watts min⁻¹ until exhaustion.

Outcome Measures: VO_2peak, heart rate (HR), and StO₂.

Results: While VO_2peak was similar among the groups, peak HR was significantly higher in both SCI groups than in the AB (P < 0.05). In active muscles (biceps brachii), no differences in the StO₂ were observed among the groups (P > 0.05). In inactive muscles (vastus lateralis), the StO₂ in the AB and the incomplete SCI began to decrease at approximately 40% of the peak work rate; however, they remained unchanged in the complete SCI. The reductions in StO₂ in the AB were significantly greater than in the incomplete SCI.

Conclusions: These results suggest that sympathetic vasoconstriction occurred in the incomplete SCI and AB, although it did not occur in the complete SCI, probably due to a reduction in sympathetic nerve activity. Sympathetic vasoconstriction in inactive muscles may not contribute to an individual’s VO_2peak regardless of their group.

目的：我们研究了增量曲臂运动 (ACE) 对活跃和不活跃肌肉组织氧饱和度 (StO ₂ ) 的影响，以及峰值摄氧量 (VO _2peak ) 与不活跃肌肉中 StO ₂变化之间的关系.

设计：观察性研究。

设置：基于社区的监督干预。

参与者：参与者是患有运动和感觉完全脊髓损伤（完全 SCI；n = 8）和运动完全但感觉不完全 SCI（不完全 SCI；n = 8）的个体，以及健全 (AB) 个体（n = 8 ) 与年龄、身高和体重指数相匹配。

干预： ACE 以增加 10 watts min ^-1的速率进行，直至筋疲力尽。

结果测量： VO _2peak、心率 (HR) 和 StO ₂。

结果：虽然两组间VO _2peak相似，但两个SCI 组的峰值HR 均显着高于AB 组（P < 0.05）。在活跃肌肉（肱二头肌）中，各组间的 StO ₂无差异（P > 0.05）。在不活动的肌肉（股外侧肌）中，AB 和不完全 SCI 中的 StO ₂在峰值工作速率的约 40% 时开始下降；但是，它们在完整的 SCI 中保持不变。AB中StO ₂的减少明显大于不完全SCI。

结论：这些结果表明交感神经血管收缩发生在不完全 SCI 和 AB 中，尽管它没有发生在完全 SCI 中，可能是由于交感神经活动减少。不活动肌肉中的交感神经血管收缩可能对个体的 VO _2peak没有贡献，无论其群体如何。