Dry Needling on the Infraspinatus Latent and Active Myofascial Trigger Points in Older Adults With Nonspecific Shoulder Pain: A Randomized Clinical Trial

Abstract

Background and Purpose:Shoulder pain is a prevalent condition in older adults. Some authors associate nonspecific shoulder pain with myofascial trigger points (MTrPs) in the infraspinatus muscle. Dry needling is recommended to relieve the MTrP pain of shoulders in the short term (<9 days). Active MTrPs dry needling improves shoulder pain and the irritability of the satellite MTrPs in the referred pain area. Nociceptive activity at a latent MTrP may influence motor activity and the sensitivity of MTrPs in distant muscles at a similar segmental level. Therefore, this study aimed to evaluate dry needling on 1 latent MTrP, in conjunction with 1 active MTrP, in the infraspinatus muscle of older adults with nonspecific shoulder pain.Methods:A single-center, randomized, single-blinded, controlled study (NCT02032602) was carried out. Sixty-six patients aged 65 years and older with trigger points in the ipsilateral infraspinatus of the painful shoulder were randomly assigned to (1) of (2) treatment groups. A session of dry needling on the infraspinatus was performed in (1) the most hyperalgesic active and latent MTrP or (2) only the most hyperalgesic active MTrP. The Numeric Rating Scale, the pressure pain threshold (primary outcome) on the anterior deltoid and extensor carpi radialis brevis latent MTrPs, and grip strength were assessed before, after, and 1 week after the intervention.Results:Statistically significant differences in the reduction of pain intensity (P ≤ .001; η2 = 0.159-0.269; d = 1.017-1.219) and the increase of pressure pain threshold (P < .001; η2 = 0.206-0.481; d = 0.870-1.924) were found for the (1) treatment group immediately and 1 week postintervention. Nevertheless, no statistical significant differences were found in grip strength (P >. 05; η2 = 0.006-0.033; d = 0.158-0.368).Conclusions:One dry needling intervention of the latent MTrP associated with the key active MTrP of the infraspinatus reduces pain intensity and the irritability of the satellite MTrPs located in the referred pain area in the short term in older adults with nonspecific shoulder pain.

Comparison of hand grip strength and upper limb pressure pain threshold between older adults with or without non-specific shoulder pain

“…For the control group, these latent MTrPs were situated bilateral in both non-painful shoulders. Shoulder pain was considered if there was pain at rest and mainly located in the glenohumeral joint between the acromion, the insertion of the deltoid muscle, and the lateral region of the scapula (Calvo, Pacheco & Hita, 2015; Calvo-Lobo et al, 2016). Non-specific shoulder pain was considered if a previous diagnosis was not present in the medical record considering structural, neurological, visceral or red flag conditions (Mitchell et al, 2005).…”

“…New treatments strategies for older adults with symptomatic shoulders are necessary (Burner et al, 2014). Therefore, non-specific shoulder pain is associated with myofascial pain syndrome (MPS), and treatment can reduce pain intensity, increase pressure pain threshold (PPT) and modify grip strength in the upper limbs of older adults (Calvo, Pacheco & Hita, 2015; Calvo-Lobo et al, 2016). …”

“…The treatment of the latent MTrP associated with the key active MTrP of the infraspinatus muscle improves pain intensity and increases the PPT of the satellite latent MTrPs located in the referred pain area over the short term (Calvo, Pacheco & Hita, 2015; Calvo-Lobo et al, 2016). …”

Physical Therapy Management in Myofascial Pain Syndrome of Shoulder Complex.

“…The excessive acetylcholine maintains a sustained depolarization of the post junctional membrane, which in turn results in an excessive release of calcium from the sarcoplasmic reticulum and sustained sarcomeres' contractions. Studies also suggested that an impaired re-uptake of calcium into the sarcoplasmic reticulum induced by calcium channel blockers may cause MTrPs 8,9 .…”

“…Superficial dry needling, which involves placing an acupuncture needle in the skin overlying an MTrPs and electrical twitch-obtaining intramuscular stimulation 21,24 .Based on previous infraspinatus studies, Trp-DN produces segmental anti nociceptive effects. On the one hand, active MTrPs-DN improves shoulder pain and the irritability of the satellite MTrPs in the referred pain area 8,25 . For patients with myofascial pain syndrome of the infraspinatus muscle and shoulder pain, dry needling of trigger points of that muscle showed an immediate reduction of pain and improvement of range of movement 26 .…”