Laser Therapy Versus Transcutaneous Electical Nerve Stimulation at Hemiplegic Shoulder Pain

Stroke is one of the most devastating neurological disorders, affecting approximately 9 million people worldwide annually. With increasing life expectancy, stroke remains a major cause of morbidity and mortality. The introduction of effective treatment strategies in the acute phase has led to increased expectations regarding prognosis. Nevertheless, secondary complications following stroke are frequently encountered and may significantly hinder the rehabilitation process.

The upper extremity is affected more frequently than the lower extremity, and functional recovery of the upper extremity is generally more challenging and slower. Shoulder problems account for a substantial proportion of upper extremity functional impairments. One of the major contributing factors to these problems is impaired shoulder biomechanics. Shoulder pain may develop within the first two weeks following stroke, although it typically occurs between one and three months after stroke.

The etiology of hemiplegic shoulder pain (HSP) is multifactorial and may involve several contributing factors, including shoulder subluxation, complex regional pain syndrome type I, biceps tendinopathy, rotator cuff abnormalities, adhesive capsulitis, and increased muscle tone. Stroke survivors frequently experience impairments in upper extremity motor function and manual dexterity, which may subsequently lead to difficulties in performing activities of daily living. Effective pain management can reduce pain intensity, enhance patients' participation in rehabilitation, and contribute to improvements in joint range of motion and functional capacity.

Various physical therapy modalities are used in the management of HSP. One such modality is laser therapy, an acronym for Light Amplification by Stimulated Emission of Radiation. The fundamental principles of laser technology are based on quantum theory and the concept of stimulated emission. The first functional laser device was developed by Theodore Maiman in 1960. Laser devices generate and amplify light through stimulated emission of radiation within a specific active medium. Laser therapy is thought to exert beneficial effects on pain reduction, joint range of motion, and upper extremity function. In clinical practice, laser therapy is used to exploit its potential regenerative, biostimulatory, analgesic, anti-inflammatory, and anti-edematous effects. Its efficacy has previously been investigated in musculoskeletal conditions such as knee osteoarthritis and adhesive capsulitis of the shoulder, as well as in patients with hemiplegia.

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological intervention used in the management of acute and chronic pain. TENS devices deliver pulsed electrical currents through electrodes placed on the skin and are generally considered safe and relatively inexpensive. Stimulation parameters, including pulse frequency and intensity, can be adjusted according to clinical requirements and may influence the therapeutic response to TENS.

The aim of this study is to investigate whether laser therapy and TENS, when administered in addition to conventional physical therapy exercises in patients with HSP following stroke, provide additional benefits in terms of pain, joint range of motion, spasticity, and upper extremity function. The study also aims to compare the efficacy of these two treatment modalities and determine whether either modality is superior to the other.

Materials and Methods

Study Design and Participants

This prospective, randomized controlled study is planned to include 60 patients aged 18-85 years who will present to the Physical Medicine and Rehabilitation Outpatient Clinic between November 2026 and September 2028. Eligible participants will have a first-ever ischemic stroke and shoulder pain.

Randomization and Blinding

Eligible participants will be randomly allocated to three groups using the sealed-envelope method, with the allocation process conducted by the same physiotherapist. Owing to the nature of the interventions, the physiotherapist administering the treatments will be aware of the participants' group assignments. However, all outcome assessments are planned to be performed by the same researcher, who will be blinded to treatment allocation.

Rehabilitation Protocol

All participants will undergo a multidisciplinary rehabilitation program consisting of 20 sessions over four weeks, with treatment administered five days per week. Conventional physical therapy exercises will be tailored to each patient's individual needs and neurological status.

The exercise program will be determined by the physiotherapist according to each patient's functional status and will include passive, active-assisted, and active range-of-motion exercises, stretching and strengthening exercises, and mobilization techniques.

Treatment Groups

Group 1: Laser therapy group (n = 20)

Participants in this group will receive laser therapy for five minutes per session, three days per week, in addition to conventional physical therapy.

Group 2: TENS group (n = 20)

Participants in this group will receive TENS for 20 minutes per session, five days per week, in addition to conventional physical therapy.

Group 3: Control group (n = 20)

Participants in this group will receive conventional physical therapy exercises alone.