The Application of Low- and Medium-Frequency Electrical Stimulation in Upper Limb Rehabilitation

Challenges Faced by Patients with Upper Limb Dysfunction

 

The hand is an essential organ for daily activities and serves as a key tool for humans to explore the external world and interact with the environment. Compared to other body parts, the hand and upper limb possess greater complexity and importance in motor functions. Therefore, upper limb motor function rehabilitation is a core focus in post-stroke rehabilitation, yet it also represents a major challenge. Patients with upper limb dysfunction caused by conditions such as stroke, spinal cord injury, or hand trauma often experience a slow recovery process due to the complexity of hand and upper limb movements. This prolonged rehabilitation journey poses a significant psychological challenge, potentially affecting patients' sense of self-fulfilment, and may lead to anxiety, depression, and other emotional issues. These negative emotions can, in turn, further diminish rehabilitation motivation and impact the overall quality of life.

What is Functional Electrical Stimulation (FES)?

Functional Electrical Stimulation (FES) is a rehabilitation technique that uses low-frequency pulsed electrical currents to stimulate one or more groups of muscles through preset programs, inducing muscle contractions or simulating normal voluntary movements. The goal of FES is to improve or restore the functions of muscles and muscle groups affected by neurological damage, thereby compensating for or correcting the loss of motor function in limbs and organs. In recent years, the application of FES has expanded significantly, especially for patients with limb dysfunction caused by stroke or spinal cord injury. Through repeated electrical stimulation, FES can not only activate motor neurons but also promote neuroplasticity in the central nervous system, helping patients gradually regain voluntary motor abilities.

3. Common Electrode Placements for FES in Limb Training

(1) Shoulder Subluxation

Patients with central nervous system injuries or high-level spinal cord injuries often experience shoulder subluxation. Strengthening the supraspinatus and the posterior part of the deltoid muscle can help prevent and improve shoulder subluxation.

 

Stimulation electrode: Placed on the posterior one-third of the deltoid muscle;

Auxiliary electrode: Placed on the supraspinatus muscle.

(2) Triceps Muscle Weakness

For patients with central nervous system disorders, using NMES to strengthen the triceps brachii can enhance elbow extension control and relieve spasticity of the biceps brachii.

Stimulation electrode: Placed below the posterior part of the deltoid muscle;

Auxiliary electrode: Placed above the olecranon (be careful to avoid stimulating the brachioradialis to prevent unwanted elbow flexion).

(3) Wrist and Finger Extensor Muscle Weakness

Due to the small size of forearm muscles, smaller electrode pads are generally recommended for stimulating the wrist and finger extensor muscles.

 

For wrist extensors:

Stimulation electrode: Placed below the lateral epicondyle of the humerus;

Auxiliary electrode: Placed proximally near the wrist joint.

 

For finger extensors:

Stimulation electrode: Placed more distally in the center of the forearm;

Auxiliary electrode: Placed proximally near the wrist joint.