Immediate Effect of Dry Needling on the Viscoelastic Properties of a Trigger Point on the Infraspinatus Muscle Measured with MyotonPRO.

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. 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. Analyses of variance showed significant decreases in tone ( < 0.001) and stiffness ( = 0.003) across time after the DN technique. Post hoc tests revealed a significant reduction in tone and stiffness from T1 to T2 ( ≤ 0.004) and no significant changes from T2 to T3 ( ≥ 0.10). At T3, only stiffness remained significantly lower compared to T1 ( = 0.013). 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.