4.1 Motor Recovery of the Lower Extremity Post Stroke
Factors that Predict Motor Recovery
Motor deficits post-stroke are the most obvious impairment (Langhorne et al. 2012) and have a disabling impact on valued activities and independence. Motor deficits are defined as “a loss or limitation of function in muscle control or movement or a limitation of movement” (Langhorne et al. 2012; Wade 1992). Given its importance, a large proportion of stroke rehabilitation efforts are directed towards the recovery of movement disorders. Langhorne et al. (2012) notes that motor recovery after stroke is complex with many treatments designed to promote recovery of motor impairment and function.
The two most important factors which predict motor recovery are:
- Stroke Severity: The most important predictive factor which reduces the capacity for brain reorganization.
- Age: Younger patients demonstrate greater neurological and functional recovery and hence have a better prognosis compared to older stroke patients (Adunsky et al. 1992; Hindfelt & Nilsson 1977; Marini et al. 2001; Nedeltchev et al. 2005).
Changes in walking ability and gait pattern often persist long-term and include increased tone, gait asymmetry, changes in muscle activation and reduced functional abilities (Wooley 2001; Robbins et al. 2006; Pizzi et al. 2007, Pereira et al. 2012). Ambulation post stroke is often less efficient and associated with increased energy expenditure (Pereira et al. 2012). Hemiplegic individuals have been reported to utilize 50-67% more metabolic energy that normal individuals when walking at the same velocity (Wooley et al. 2001).
For mobility outcome, trunk balance is an additional predictor of recovery (Veerbeek et al. 2011). Nonambulant patients who regained sitting balance and some voluntary movement of the hip, knee and/or ankle within the first 72 hours post stroke predicted 98% chance of regaining independent gait within 6 months. In contrast, those who were unable to sit independently for 30 seconds and could not contract the paretic lower limb within the first 72 hours post stroke had a 27% probability of achieving independent gait.