Kinesio Taping for Upper Trapezius Myofascial Trigger Points

Overview

Myofascial pain syndrome is one of the most common causes of musculoskeletal pain, and the upper trapezius is the muscle most frequently affected in the neck and shoulder region. Kinesio taping is a non-invasive, painless and low-cost method that is increasingly used in the treatment of myofascial trigger points, but its true therapeutic effect beyond placebo has not been clearly established. The purpose of this randomized, sham-controlled trial is to evaluate the effectiveness of kinesio taping applied with the muscle inhibition technique on myofascial trigger points of the upper trapezius muscle. Forty patients with an active myofascial trigger point in the upper trapezius will be randomly assigned in a 1:1 ratio to receive either therapeutic kinesio taping or sham taping (20 patients per group). Both groups will receive four applications over two weeks (twice weekly). The primary outcome is the pressure pain threshold measured with a digital algometer. Secondary outcomes are pain intensity, trapezius muscle thickness measured by B-mode ultrasonography, and muscle stiffness assessed by strain elastography. All outcomes are assessed at baseline, on day 3, and at the end of the two-week treatment period.

Myofascial pain syndrome is characterized by hyperirritable nodules located within taut bands of skeletal muscle, known as myofascial trigger points. The upper trapezius is the most commonly involved muscle in the neck and shoulder girdle, and trigger points in this region are an important cause of neck pain, restricted mobility and loss of productivity. Kinesio taping has become increasingly popular in the management of myofascial trigger points because it is non-invasive, painless, inexpensive and has few adverse effects. Systematic reviews and meta-analyses suggest that kinesio taping reduces pain intensity and improves pressure pain threshold and range of motion in myofascial pain syndrome. However, the taping techniques used across studies differ substantially. Two techniques predominate: the space correction technique, in which strips are applied over the trigger point in a star-shaped pattern, and the muscle inhibition technique, in which a single I-strip is applied along the muscle fibres from insertion to origin with low tension. A trial directly comparing these two techniques found no significant difference between them, whereas a sham-controlled trial found that the space correction technique was not superior to sham at 72 hours. Studies using the inhibition technique have reported significant improvements in pressure pain threshold. Because the inhibition technique is mechanistically aimed at reducing muscle tone and is supported by stronger evidence, it was selected for this trial. In addition, outcome measures in previous studies have been largely subjective. Pressure algometry provides a quantitative measure of the mechanical sensitivity of the trigger point, while B-mode ultrasonography allows measurement of muscle thickness and ultrasound elastography allows objective assessment of tissue stiffness. Strain elastography with calculation of the strain ratio has shown good reliability in patients with upper trapezius myofascial pain syndrome and can differentiate active trigger points, latent trigger points and control sites. To the best of our knowledge, no sham-controlled randomized trial has evaluated kinesio taping of upper trapezius myofascial trigger points using pressure pain threshold as the primary outcome together with muscle thickness and strain elastography as objective secondary outcomes. A sham-controlled design was chosen because sham taping alone may produce a substantial placebo response, and only a sham comparator can isolate the true therapeutic effect. In the intervention group, a single I-shaped kinesio tape strip will be applied from insertion to origin along the upper trapezius with 15-25% tension while the muscle is held in a stretched position. In the sham group, an identical tape of the same brand, colour and size will be applied to the same region without therapeutic tension and with the neck in a neutral position, so that the skin convolutions responsible for the therapeutic effect are not produced. Both groups will receive four applications over two weeks (twice weekly); at each session the existing tape is removed and a new tape applied, so the tape remains on the skin continuously throughout the treatment period. Patients will be randomly allocated in a 1:1 ratio using a computer-generated random number list. The study is single-blind: the practitioner applying the tape cannot be blinded due to the nature of the intervention and therefore takes no part in any assessment. All pain, pressure pain threshold and ultrasonographic measurements will be performed by a researcher blinded to group allocation, after tape removal.