EMG Biofeedback and NMES of Deltoid in Patients With rTSA

National Taiwan University

Status: Enrolling

Conditions: Reverse Shoulder Replacement

Treatments: Device: neuromuscular electrical stimulation; Device: biofeedback

Study type: Interventional

Funder types: Other

Identifiers

NCT06873022

202403141DINE

Details and patient eligibility

About

The effect of NMES and surface electromyography (sEMG) biofeedback on the deltoid and associated scapular muscles in scapular kinematics and muscle activation in individual post rTSA

Full description

Reverse total shoulder arthroplasty (rTSA) has been the optimal treatment for massive irreparable rotator cuff tears and cuff tear arthropathy. Since scapular kinematics alteration was associated with shoulder disorders, scapular kinematics had been characterized in individuals post rTSA with more upward rotation, external rotation, and posterior tilt of the scapula. In addition, the average scapulohumeral rhythm ranged from 1.1 to 1.6, indicating lower glenohumeral joint movements and higher scapulothoracic movements. It supposed that more scapula upward rotation without adequate humeral elevation can result in the scapula notching. Therefore, strategy to decrease scapular movement or increase humeral movements during arm movements may prevent scapula notching. To compensate for rotator cuff deficiency, the deltoid muscle plays a crucial role post rTSA. Enhancing deltoid function can be accomplished through the use of biofeedback or neuromuscular electrical stimulation (NMES). However, the effect of NMES and surface electromyography (sEMG) biofeedback on the deltoid and associated scapular muscles in scapular kinematics, muscle activation, and muscle balance ratio in individual post rTSA remained unclear. Therefore, the objectives in this study would to (1) determine the immediate effects of NMES with EMG biofeedback to deltoid (D) on the muscle activation of upper trapezius (UT), lower Trapezius (LT) and serratus Anterior (SA) as well as the scapular kinematics (upward/downward rotation, external/internal rotation, anterior/posterior tilting) (2) evaluate the immediate effects of NMES with EMG biofeedback on the muscle balance ratios (D/UT, D/LT, D/SA) and the scapulohumeral rhythm (SHR) during arm elevation in the scapular plane at different range of motion.

Enrollment: 34 estimated patients

Sex: All

Ages: 20 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• (1) age between 20 to 85 years old
• (2) undergoing primary reverse shoulder arthroplasty
• (3) shoulder abduction in scapular plane above 90 degrees
• (4) above 3 months following rTSA

Exclusion criteria

• (1) a history of other shoulder surgery on the rTSA shoulder
• (2) a revision rTSA
• (3) a surgery shoulder muscle tendon transfer
• (4) neuromuscular diseases
• (5) cognitive disorders
• (6) contraindications for NMES

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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34 participants in 2 patient groups

biofeedback

Experimental group

Description:

sEMG biofeedback: Subjects were instructed to monitor the sEMG signals of the D/UT balances ratio on the screen and maintain the D/UT balances ratio above the threshold during arm elevation and lowering. The threshold was set at 1 standard deviation of the ratio average at baseline (before intervention).

Treatment:

Device: biofeedback

neuromuscular electrical stimulation

Experimental group

Description:

NMES: Two electrode pads were placed on the anterior, middle, and posterior deltoid boundary lines and at a distance of 1cm distal to the lateral margin of the acromion. The operator palpated the deltoid muscle contraction and asked the subjects to perform arm elevation task with NMES. (frequency of 35 Hz and a duration of 250 microseconds.) A verbal cue was given during both th A verbal cue was given during both the sEMG biofeedback and NMES interventions: "Lengthen your arm as if you want to touch the ground, the scapula keeps in the neutral position, and then elevate your arm." Each intervention consisted of 3 sets of 10 repetitions per set, with a 1-minute rest between sets.

Treatment:

Device: neuromuscular electrical stimulation