Neural mobilization has been used to treat individuals with musculoskeletal and neuromuscular pathologies, but research on neural mobilization in sports rehabilitation is scarce. Furthermore, there have been no studies investigating the effects of neural gliding on sport performance. The purpose of this study was to examine the differences between the acute effects of sciatic nerve gliding and lower extremity dynamic stretching exercises on hamstring flexibility and athletic performance. A cross-sectional, quasi-experimental design with block assignment was used. Twenty-seven (16 males, 11 females, age: 23.6 ± 2.65, height (m): 1.74 ± 0.12, weight (kg): 73.73 ± 16.09) healthy college students volunteered for the study. The neural gliding group had 14 subjects and the dynamic stretching group had 13 subjects. Participants performed a jogging or walking up stairs warm up at a self-selected pace prior to testing. Baseline data was obtained for each of the following measurements: bilateral hamstring flexibility using the active straight leg raise test measured by a digital inclinometer, vertical jump height, 20-yard shuttle run and 10 and 20-yard dash sprint. The participants then performed one of the assigned five-minute stretching protocol, bilateral sciatic neural gliding or dynamic stretching of the lower extremities, followed by the post-test data collection of the same measures. There were no significant group by time interaction for any of the six measurements (2 x 2 repeated measures ANOVA). However, significant time differences, pre-test vs post-test for all participants as one group, for right hamstring length (p = .001), left hamstring length (p = .002) and vertical jump (p = .028) were observed. Post hoc paired t-tests found a significant increase between the pre and post-tests in right hamstring flexibility, (p = .011) in the dynamic stretching group and left hamstring flexibility of participants in the neural gliding condition, (p = .004). When analyzing the groups individually, pre-test vs post-test, a significant difference in vertical jump was not observed in either group. Similar improvement in hamstring flexibility with both dynamic stretching and neural gliding exercises without a negative effect on three sports performance tests was demonstrated. Therefore, athletic performance will not be negatively affected by a pre-participation warm-up which includes neural gliding, but more research is needed. Level 3.

(-)-Epicatechin is a polyphenol previously shown to enhance vascular health. The purposes of the current studies were to determine the effect of acute (-)-epicatechin supplementation on local vasodilation in conjunction with resistance exercise (study 1) and on high-intensity exercise performance (study 2). For study 1, 11 men participated in two resistance exercise sessions, where they performed three sets of barbell curls while consuming 200 mg of 98% pure (-)-epicatechin or placebo. Measurements of total serum nitrate/nitrite and brachial artery diameter were acquired at baseline (pre-supplement), 90 min after supplement consumption (post-supplement), immediately post-exercise (post-exercise), and 30 min post-exercise (30 min post-exercise). For serum nitric oxide metabolites, no significant interaction between supplement and time nor significant main effect of time was observed (p = 0.38 and p = 0.20; respectively). For brachial artery diameter, no significant interaction between supplement and time was observed (p = 0.24). A significant main effect of time was observed for brachial artery diameter (p < 0.01) with post-exercise brachial artery diameter significantly greater diameter than all other time points (all p < 0.01). For study 2, six women and five men completed the 15.5 CrossFit^® Open Workout three times. A familiarization session was performed first where the workout was performed without the consumption of a supplement. In a randomized, balanced fashion, 100 mg of 98% pure (-)-epicatechin or cellulose (placebo) was consumed two times per day for two days before testing sessions two and three. On the day of testing sessions two and three, 60 to 90 min before completing the workout, 200 mg of the assigned supplement was ingested with water. No significant difference was observed for time to complete the workout between testing sessions (p = 0.49). In conclusion, under the conditions of the current studies, acute (-)-epicatechin supplementation did not augment vasodilation in combination with resistance exercise, nor did it increase exercise performance in humans.

The purpose of this study was to examine differences between a free-weight squat (FWS) and machine squat (MS) during an initial resistance training phase for augmentation of performance tests in recreationally active women. Twenty-seven women (22.7 ± 3.5 years) were block-randomized to three groups: FWS, MS, or control (CON) and completed pre- and post-testing sessions consisting of the squat one-repetition maximum (1-RM), vertical jump, pro-agility test, zig-zag change-of-direction (COD) test, and 30-meter sprint. Participants trained two sessions per week for six weeks by performing jumping, sprinting, and COD drills followed by FWS, MS, or no squats (CON). Peak jump power increased for CON (p = 0.03) and MS (p < 0.01) groups. Change in peak jump power was greater for the MS group compared with the FWS group (p = 0.05). Average jump power increased for the MS group (p < 0.01). Change in average jump power was greater for the MS group compared with the CON group (p = 0.04). Vertical jump height, pro-agility, 30-meter sprint, and zig-zag COD tests improved over time (p < 0.01), with no difference between groups (p > 0.05). Machine squat training maximized jumping power compared with FWS training and CON. Both resistance training groups and the CON group improved equally in the pro-agility, 30-meter sprint, and zig-zag COD tests. Machine squat training may provide performance-enhancing benefits of equal or superior value to those obtained with free-weight squat training in recreationally active women during an initial training mesocycle. These findings also stress the importance of task-specific training in this population of untrained women, as the control group improved in terms of performance to the same degree as both resistance training groups.

Background and Purpose: Anterior cruciate ligament injuries are prevalent among the athletic population, imposing a heavy economic burden, and the risk of re-injury. Most current biomechanical screening tasks are performed in the sagittal plane, and there is a need for more screening tools that assess sports specific movements in the frontal plane. The purpose of this study was to determine the reliability of and examine differences between sexes in the performance of the Lateral Bound Test (LBT). Materials/Methods: Each subject performed three trials of a LBT which included jumping laterally from one leg over a hurdle and landing on the opposite leg. Two cameras were placed six feet from the landing marker. Maximum dynamic knee valgus using the frontal plane projection angle and knee flexion angle at initial contact and maximal knee flexion were measured upon landing leg using 2D video analysis software. Additionally, video of 10 individuals’ trials were analyzed twice with one week between the analyses to obtain intra-rater reliability while 12 participants were retested one week later to determine test-retest reliability. Results: Thirty healthy subjects, 16 males, 14 females participated. Intra-rater reliability was determined to be excellent for all variables (ICC>0.96). In contrast, the test-retest reliability had greater disparity. Test-retest reliability ranged from poor (ICC = 0.47) to excellent (ICC > 0.90). Significant differences existed between the sexes, including males being significantly taller, weighing more, and demonstrating greater bilateral dynamic knee valgus (p < 0.05). No significant differences existed between sexes for knee flexion angles. Conclusion: The new LBT had excellent intra-rater reliability for assessing dynamic knee valgus and initial and maximum knee flexion angle when performing a functional movement in the frontal plane. Furthermore, males landed with more dynamic knee valgus than females which is contradictory to what has been observed with functional screening tools performed in the sagittal plane. Level of Evidence: 3b (reliability study)

Article: Effects of lower extremity rotation on muscle activity during heel-raise exercise - Gazzetta Medica Italiana - Archivio per le Scienze Mediche 2021 April;180(4):107-13 - Minerva Medica - Journals