Journal CME, October 2023: Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility.-Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility

Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility

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This study investigates muscle oxygenation dynamics in the paretic (affected) and nonparetic (unaffected) legs during aerobic exercise in individuals with chronic stroke and their implications for mobility. Conducted by researchers from the University of Toronto and supported by the Heart and Stroke Foundation of Canada, the study aimed to understand how muscle oxygenation, representing the balance between oxygen delivery and utilization, differs between these legs and its relationship with mobility.<br /><br />Twelve male participants, about 30.8 months post-stroke and aged around 63.9 years, engaged in treadmill exercise and a six-minute walk test (6MWT) while muscle oxygenation in the vastus lateralis of each leg was measured using near-infrared spectroscopy (NIRS). Notably, the desaturation slope, which indicates the rate of oxygen decline at the onset of exercise, was significantly steeper in the paretic leg compared to the nonparetic leg. This finding suggests that the paretic leg is less effective at matching oxygen demand and extraction during the onset of exercise. It implies that stroke survivors might benefit from an immediate cardiovascular warm-up before engaging in moderate-intensity activities to enhance oxygen delivery efficiency.<br /><br />The study found no significant differences in muscle oxygenation between the legs during the 6MWT, likely due to the nonparetic leg compensating more for workload disparities during overground walking. Additionally, there was no significant correlation between 6MWT distance and muscle oxygenation levels, indicating that mobility impairments in this population are not solely influenced by muscle oxygenation.<br /><br />The findings highlight the need for tailored exercise prescriptions for stroke survivors, emphasizing the importance of warm-up routines. Further research comparing post-stroke individuals to healthy controls is recommended to validate these results and refine rehabilitation protocols.

Keywords

muscle oxygenation

paretic leg

nonparetic leg

aerobic exercise

chronic stroke

mobility

near-infrared spectroscopy

cardiovascular warm-up

6-minute walk test

rehabilitation protocols