Myofascial trigger points alter the modular control during the execution of a reaching task: a pilot study

Prevalence of Myofascial Trigger Points in Isolated Idiopathic Cervical Dystonia: A Possible Contributor to Pain, Movement and Disability

BACKGROUND

Myofascial trigger points (TrPs) are hypersensitive points located in a tight band of muscle that, when palpated, produce not only local pain but also referred (distant) pain. The role of TrPs in patients with cervical dystonia (CD) has not been investigated.

OBJECTIVE

To identify the presence of TrPs in patients with isolated idiopathic CD and their association with pain.

METHODS

Thirty-one patients (74.2% women; age: 61.2 years, SD: 10.1 years) participated. TrPs were explored in the sternocleidomastoid, upper trapezius, splenius capitis, levator scapulae, anterior scalene, suboccipital, and infraspinatus muscles. Clinical features of CD were documented as well as the presence of pain. The severity of dystonia and its consequences were assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS).

RESULTS

The mean number of TrPs for each patient was 12 (SD:3), with no differences between patients with pain (n = 20) and those without pain (n = 11). Active TrPs were only found in patients with pain (mean: 7.5, SD:4). Latent TrPs were found in both groups but were more prevalent (P < 0.001) in patients without pain (mean: 11, SD:3.5) than in those with pain (mean: 5, SD:3.5). The number of active TrPs or latent TrPs was positively associated with the TWSTRS disability subscale and the TWSTRS total score. The number of active, but not latent, TrPs was associated with worse scores on the TWSTRS pain subscale.

CONCLUSION

Active TrPs were present in patients with CD reporting pain, while latent TrPs were present in all CD patients, irrespective of their pain status. The numbers of active/latent TrPs were associated with disability. TrPs could act as pain generators in CD and also contribute to the involuntary muscle contractions characteristic of dystonia.

No Evidence of Short-term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients

OBJECTIVE

The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain (USP) patients.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with USP were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold, glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately, and 72 hours after the intervention in the infraspinatus and deltoid muscles.

RESULTS

A single application of real dry needling resulted in lower pain intensity scores and a larger range in glenohumeral internal rotation 72 hours after the intervention in comparison with sham dry needling. No differences in pressure pain threshold or muscle activity were observed due to the intervention.

DISCUSSION

A single application of real dry needling resulted in clinically significant changes in the short term. No differences were detected in muscle activation in the infraspinatus or deltoid muscles. Complementary interventions and longer follow-up times may be required to observe changes in muscle activity.

[Feeling stiff…but what does it mean objectively? : Can you measure muscle tension?]

Almost everyone is familiar with "tense muscles", but what is muscle tension physiologically behind? Are tense muscles more active; do they have problems relaxing? Are they harder or stiffer than asymptomatic muscles? In this work, current evidence regarding the activity and stiffness of tense neck muscles is presented. Further, measurement methods and their limitations are explained. These limitations reveal the shortcomings of the current knowledge and the need for further research. Finally, a recently funded research project on the measurement of tense muscles is presented.

Modular reorganization of gait in chronic but not in artificial knee joint constraint

It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. The aims of this study were to investigate 1) the effects of an artificial knee joint constraint on the modular organization of gait in healthy subjects; and 2) the differences in modular organization between healthy subjects with an artificial knee joint constraint and people with a similar but chronic knee joint constraint. Eleven healthy subjects and eight people with a chronic knee joint constraint walked overground at 1 m/s. The healthy subjects also walked with a constraint limiting knee joint movement to 20°. The total variance accounted (tVAF) for one to four synergies and modular organization were assessed using surface electromyography from 11 leg muscles. The distribution of number of synergies were not significantly different between groups. The tVAF and the motor modules were not significantly affected by the artificial knee constraint. A higher tVAF for one and two synergies, as well as merging of motor modules were observed in the chronic knee constraint group. We conclude that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that merging of motor modules may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.NEW & NOTEWORTHY It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. This study showed that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that modular reorganization may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.

Effects of trigger point dry needling on lateral epicondylalgia of musculoskeletal origin: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis evaluated the effect of dry needling alone or combined with other treatment interventions on pain, related-disability, pressure pain sensitivity, and strength in people with lateral epicondylalgia of musculoskeletal origin.

DATA SOURCES

MEDLINE, CINAHL, PubMed, PEDro, Cochrane Library, SCOPUS and Web of Science databases from their inception to 5 April 2020.

REVIEW METHODS

Randomized controlled trials collecting outcomes on pain, related-disability, pressure pain thresholds, or strength where one group received dry needling for lateral epicondylalgia of musculoskeletal origin. The risk of bias was assessed by the Cochrane Guidelines, methodological quality was assessed with the PEDro score, and the quality of evidence by using the GRADE approach.

RESULTS

Seven studies including 320 patients with lateral epicondylalgia were included. The meta-analysis found that dry needling reduced pain intensity (SMD ‒1.13, 95%CI ‒1.64 to ‒0.62) and related-disability (SMD ‒2.17, 95%CI ‒3.34 to ‒1.01) with large effect sizes compared to a comparative group. Dry needling also increased pressure pain thresholds with a large effect size (SMD 0.98, 95%CI 0.30 to 1.67) and grip strength with a small size effect (SMD 0.48, 95%CI 0.16 to 0.81) when compared to a comparative group. The most significant effect was at short-term. The risk of bias was generally low, but the heterogenicity of the results downgraded the evidence level.

CONCLUSION

Low to moderate evidence suggests a positive effect of dry needling for pain, pain-related disability, pressure pain sensitivity and strength at short-term in patients with lateral epicondylalgia of musculoskeletal origin.

LEVEL OF EVIDENCE

Therapy, level 1a.

REGISTRATION NUMBER

OSF Registry - https://doi.org/10.17605/OSF.IO/ZY3E8.