Effects of Dry Needling on Spinal Reciprocal Inhibition

Abstract

<h3>Research Objectives</h3> Spinal reciprocal inhibition is an important spinal mechanism of motor control. It is often impaired in persons after stroke, negatively impacting locomotion; at the same time, it changes in response to therapeutic interventions (e.g., FES). An increasing number of physical therapists worldwide have been administering trigger point deep dry needling (DDN) to treat post-stroke spasticity. Yet, currently, effects of DDN on spinal somatosensory processing are not well understood. Thus, to understand neurophysiological mechanisms of DDN, we are investigating the effects of DDN on spinal pathways in persons with and without stroke. <h3>Design</h3> Before and 0, 90 minutes, and 72 hours after DDN of the medial gastrocnemius (MG) at myofascial trigger points, reciprocal inhibition of the soleus, MG and lateral gastrocnemius (LG) was examined while the participant stood and maintained his/her standing posture and triceps muscle activity. Passive ankle range of motion (ROM) was also measured before and after DDN. <h3>Setting</h3> University. <h3>Participants</h3> 11 adults 22-57 years old (median 37.5) without known neurological conditions. <h3>Interventions</h3> Trigger point dry needling to medial gastrocnemius <h3>Main Outcome Measures</h3> Reciprocal inhibition of ongoing muscle activity elicited by common peroneal nerve (CPN) stimulation. ROM. <h3>Results</h3> In the MG and LG, there was no systematic changes in the amount of inhibition across participants or measurement times. Soleus inhibition elicited by suprathreshold CPN stimulation was increased significantly at 0 minute and 72 hours post DDN (p>0.05). Ankle dorsiflexion ROM was increased by 4 deg at 0 minutes and 72 hours post DDN. <h3>Conclusions</h3> DDN alters soleus inhibition, which may partially explain increased ankle ROM post DDN. In order to understand how DDN affects reciprocal inhibition in the stroke-impaired CNS, studies of individuals after stroke are currently underway. <h3>Author(s) Disclosures</h3> The authors have no conflicts of interest to declare.