Using wavelet analysis, a technique for time-frequency decomposition, accompanied with principal component analysis, we can track the recruitment patterns of different motor unit types such as slow and fast motor units from surface electromyography in individuals with neurological impairments. There is evidence that fiber type composition changes occur due to stroke, cerebral palsy, and spinal cord injury and since slow and fast fibers can have different properties, altered recruitment patterns may result in impaired muscle contraction during tasks such as walking.