Byrne, DJ, Browne, DT, Byrne, PJ, and Richardson, N. Interday reliability of the reactive strength index and optimal drop height. J Strength Cond Res 31(3): 721-726, 2017-The purpose of this study was to investigate the interday reliability of the reactive strength index (RSI) and optimal drop height (ODH) identification from multiple drop heights. Nineteen male trained hurling players (23.1 ± 2.9 years, 83.1 ± 15.5 kg, and 182.5 ± 4.89 cm) completed 2 maximal depth jumps from 4 incremental drop heights (30, 40, 50, and 60 cm), over 2 separate testing sessions 48 hours apart. The RSI and ODH were analyzed for reliability using intraclass correlation coefficient (ICC) and coefficient of variation (CV). The RSI and ODH both demonstrated good reliability with ICC ≥0.80 (0.87 and 0.81) and CV ≤10% (4.2 and 2.98), respectively. The results of this study support the use of an incremental depth jump protocol to find the RSI and ODH in trained hurlers. It is recommended that the incremental depth jump protocol be used when assessing an athlete's reactive strength, as it allows a reactive strength profile, maximum RSI, and an ODH to be determined, all of which can provide vital information when determining an athletes training intensity and load.

The purpose of this study was to firstly 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 prior to performance. Forty male athletes were assigned to four 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; familiarisation, baseline, immediately after DN, 48, 72 and 96 hours post 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 ANOVA was used for statistical analysis. Results showed a significant increase in jump height in group 2 (gastrocnemius muscle only) from immediately post to 48 hours post 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 post to 48 hours post DN of the gastrocnemius muscle only. This study suggests a likely immediate decrease in jump performance following DN, with levels increasing above baseline between 48 hours and 96 hours, which may have clinical significance.