Devereux, F, O'Rourke, B, Byrne, PJ, Byrne, D, and Kinsella, S. Effects of myofascial trigger point release on power and force production in the lower limb kinetic chain. J Strength Cond Res 33(9): 2453-2463, 2019-The purpose of this study was to first investigate the effects of treating latent myofascial trigger points (MTrPs) in the lower limb kinetic chain with respect to performance during sporting actions, as opposed to the traditional goal of pain management with active MTrPs. The second aim was to investigate the effects of dry needling (DN) on performance parameters over time to establish treatment timeframe guidelines before performance. Forty male athletes were assigned to 4 groups; rectus femoris DN (group 1), medial gastrocnemius DN (group 2), rectus femoris and medial gastrocnemius DN (group 3), and no DN (group 4). Subjects completed 6 sessions; familiarization, baseline, immediately after DN, 48, 72, and 96 hours after intervention. Subjects performed squat jumps at 5 incremental loads and were recorded using the My Jump app (iOS) for jump height, power output, optimal force, and optimal velocity. A between-within subject's analysis of variance was used for statistical analysis. Results showed a significant increase in jump height in group 2 (gastrocnemius muscle only) from immediately after to 48 hours after intervention (p = 0.01); however, no other statistical significance was observed. From 48 hours onward, a trend for improved performance was observed, with jump height, power, and velocity showing trivial increases. This study found improved jump performance from immediately after to 48 hours post-DN of the gastrocnemius muscle only. This study suggests a likely immediate decrease in jump performance after DN, with levels increasing above baseline between 48 and 96 hours, which may have clinical significance.