Immediate Effect of Dry Needling on the Viscoelastic Properties of a Trigger Point on the Infraspinatus Muscle Measured with MyotonPRO
Authors: Melanie Roch, Melanie Morin, Nathaly Gaudreault
Universite de Sherbrooke, Faculte de medecine et des sciences de la sante, Ecole de Readaptation, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Quebec, Canada
Journal: Physiotherapy Canada - June 2022, e20200095, Advance access article (DOI: 10.3138/ptc-2020-0095)
Field & Applications:
- Treatment evaluation
- Complementary and Alternative Medicine
- Musculoskeletal disorder
Purpose: This article investigates the immediate effects of a dry needling (DN) puncture on the viscoelastic properties (tone, stiffness, elasticity) of a trigger point (TP) in the infraspinatus muscle in non-traumatic chronic shoulder pain.
Method: Forty-eight individuals with non-traumatic chronic shoulder pain were recruited. The presence of a TP in the infraspinatus muscle was confirmed by a standardized palpatory exam. The viscoelastic properties were measured with a MyotonPRO device at baseline (T1), immediately after DN (T2), and 30 minutes later (T3). A DN puncture was applied to the TP to obtain a local twitch response while performing the technique.
Results: Analyses of variance showed significant decreases in tone (p < 0.001) and stiffness (p = 0.003) across time after the DN technique. Post hoc tests revealed a significant reduction in tone and stiffness from T1 to T2 (p ≤ 0.004) and no significant changes from T2 to T3 (p ≥ 0.10). At T3, only stiffness remained significantly lower compared to T1 (p = 0.013).
Conclusions: This study brings new insights on the immediate mechanical effect of DN on tone and stiffness of TPs. Whether these effects are associated with symptom improvement and long-term effects still needs to be verified.
Figure 1. The MyotonPRO device.
Keywords: elasticity, measurement, muscle tonus, myofascial trigger point
This study provides evidence that applying a single needle insertion in a TP in the infraspinatus muscle in patients with chronic, non-traumatic shoulder pain can immediately decrease the tone and stiffness of the TP. It also brings evidence for the use of MyotonPRO to detect changes in the viscoelastic parameters of a TP after a DN intervention. More research is needed to verify the long-term effects of a needle insertion on the viscoelastic parameters of a TP. Randomized clinical trials need to be performed to confirm the efficacy of DN in different muscle groups and the long-term effects.