Reinnervation after axonal degeneration is a slow, conditional process. Proximal nerve fibers can sprout and grow along the guiding pathways created by Schwann cells to reach denervated target muscles or skin, but this takes time. In humans, the regrowth rate is about 1–3 mm per day, so even under favorable conditions it can take months to reconnect far targets, and longer if there are obstacles. The likelihood and speed of recovery depend on many factors: how far the target is, whether the distal nerve environment and motor endplates remain viable, the presence of scar tissue or a gap that blocks growth, and the person’s age and health (such as diabetes, smoking, nutrition). When the path is clear, reinnervation can occur without surgery; if the injury creates a significant gap or severe disruption, surgical repair may be needed, but reinnervation is still possible in many cases. So the true statement is that reinnervation can occur but takes time and depends on many factors.

Progress in an electrotherapy course is best tracked with a holistic set of measures that reflect symptoms, function, and how the patient tolerates treatment. Monitoring pain levels, range of motion, muscle strength, how well the patient can perform daily tasks, changes in edema, and the patient’s own sense of comfort and tolerance gives a complete picture of improvement or areas needing adjustment. This multi-domain approach matters because gains in one area don’t always translate to overall functional benefit, and patient comfort and safety are essential for continuing therapy. For example, pain might lessen quickly, but if range of motion or strength doesn’t improve, the functional value is limited; conversely, strong improvements in strength without reducing pain or improving function may still limit daily activity. Focusing on only one metric, like ROM, or only counting sessions, or ignoring patient feedback, misses key information needed to guide treatment safely and effectively.

Electrical stimulation activates motor units in a reverse pattern compared to voluntary effort: fast-twitch Type II fibers, which have larger-diameter axons and lower impedance to the external current, are recruited first. This means Type II fibers come online before Type I fibers when a stimulus is applied. The electrical pulse acts across the muscle area, causing motor units to be activated nearly at the same time, so firing is synchronous rather than staggered across units as in natural, voluntary contraction. The rate at which these fibers fire is determined by how fast the stimulator delivers pulses—the higher the stimulation rate, the higher the firing rate of the recruited units, leading from individual twitches toward a smooth, tetanic contraction. So, the pattern described—Type II first, synchronous firing, and higher firing rate that rises with the stimulator rate—best fits electrically stimulated contraction.

In NMES re-education, you control where and how the current activates the muscle by choosing the right electrode size and placement. The size of the pads matters because it changes current density: a pad that fits the target muscle well delivers the electrical charge more evenly and avoids excessive concentration that can cause discomfort, while also avoiding spread to neighboring muscles. The placement should be over the muscle belly or at a motor point—the spot where the nerve fibers supplying that muscle are most accessible near the surface. Stimulation here produces a clear, functional contraction with less current, which is ideal for retraining muscle function. Why this is the best fit: placing pads over bone or tendon won’t reliably recruit the target muscle, and aiming at a nerve or using a fixed size without regard to the muscle’s size can lead to ineffective or uncomfortable contractions. Electrode size is not determined by color or patient age, but by the muscle you want to recruit and the goal of achieving a strong, tolerable, and controllable contraction.