Evidence-Based: Physical Therapy Pelvic Floor

Muscle activity is thoroughly dependent on neural control. ‘Denervated’ muscle atrophies and turns into fibrotic tissue. Muscle – like every tissue – consists of cells (muscle fibres). But the functional unit within striated muscle is not a single muscle cell, but a motor unit. A motor unit consists of one alpha (or ‘lower’) motor neuron (from the motor nuclei in spinal cord), and all the muscle cells this motor neuron innervates. The motor unit – in other words – is the basic functional unit of the somatic motor system; control of a muscle means control of its motor units. Thus, in discussing neural control of muscle, we really only need to consider the motor neurons in the spinal cord and all the influences they are exposed to. The function of pelvic floor and sphincter lower motor neurons is organized quite differently from other groups of motor Neurons. In contrast to the reciprocal innervations that is common in limb muscles, the neurons innervating each side of the PFM hav...