Enhancing soccer goalkeepers penalty dive kinematics with instructional video and laterality insights in field conditions.

This study aimed to analyze the effect of laterality and instructional video on the soccer goalkeepers' dive kinematics in penalty. Eight goalkeepers from youth categories (U15, U17, U20) were randomly divided into control (CG) and video instruction groups (VG). The latter performed 20 penalty defense trials on the field with balls launched by a machine, ten before and after watching a video instruction to improve the diving kinematics. The CG only performed the dives. Three cameras recorded the collections. A markerless motion capture technique (OpenPose) was used for identification and tracking of joints and anatomical references on video. The pose data were used for 3D reconstruction. In the post-instruction situation, the VG presented differences in comparison to the CG in the: knee flexion/extension angle, time to reach peak resultant velocity, frontal step distance, and frontal departure angle, which generated greater acceleration during the dive. Non-dominant leg side dives had higher resultant velocity during 88.4 - 100% of the diving cycle, different knee flexion/extension angle, and higher values ​​in the frontal step distance. The instructional video generated an acute change in the diving movement pattern of young goalkeepers when comparing the control and the video instruction group in the post condition.

An investigation of the contribution of different turn speeds during standing turns in individuals with and without Parkinson's disease.

Issues around turning can impair daily tasks and trigger episodes of freezing of gait in individuals with Parkinson's disease (PD). Slow speeds associated with aging produce a more en-bloc movement strategy which have been linked with falls while turning. However, the influence of speed of turning on the complex whole-body coordination considering eye movements, turning kinematics, and stepping characteristics during turning has not been examined. The aim of this study was to investigate if individuals with PD have a different response to changes in turning speed compared to healthy older adults during 180° standing turns. 20 individuals with PD and 20 healthy age matched adults participated in this study. Data were collected during clockwise and counter-clockwise turns at three self-selected speeds in a randomised order: (a) normal; (b) faster than normal; and (c) slower than normal. Eye movement and turning kinematics were investigated using electrooculography and Inertial Measurement Units. Mixed Model Analysis of Variance (MM ANOVA) tests with post hoc pairwise comparisons were performed to assess the differences between groups and turning speed. In addition, further post hoc Repeated Measures ANOVA (RM ANOVA) tests were performed if any significant interactions were seen between groups and turning speed. Significant interaction effects were found in eye movement and turning kinematics, and the RM ANOVA showed significant main effects for turning speeds within the PD and the control groups. Turning slowly resulted in similar alterations in eye movement, turning kinematics and stepping characteristics in the PD group and the healthy controls. However, individuals with PD showed a different response to the healthy controls, with a greater delay in eye movement and onset latency of segments in turning kinematics and step variables between the different speeds. These findings help our understanding regarding the turning strategies in individuals with PD. The incorporation of guidance with regard to faster turning speeds may be useful in the management of individuals with PD. Clinical training using different turn directions and speeds may improve coordination, increase confidence and reduce the risk of falling.

Effects of 8 weeks of masticatory muscles focused endurance exercises on women with oro-facial pain and temporomandibular disorders: A placebo randomised controlled trial.

BACKGROUND: Exercises are used to treat temporomandibular disorders (TMD), but they are often assessed with other therapies. Local endurance exercises may alter the resistance to fatigue and pain. OBJECTIVE: To assess the effects of an 8-week protocol of local endurance exercises of masticatory muscles on muscle excitation, force response, perceived pain and over muscle efficiency. DESIGN: Randomised controlled trial. SETTING: Ambulatory care. SUBJECTS: In a placebo randomised controlled trial, 46 women with TMD and oro-facial pain were randomised into intervention group and placebo group. The intervention group received a protocol of biting endurance exercises, controlled by biofeedback. The placebo group received a placebo (simulated laser therapy). MAIN OUTCOME MEASURES: The primary outcomes were collected at baseline, 4 weeks and 8 weeks. Pain was assessed through visual analogue scale (VAS) and pressure pain thresholds (PPT). Bite force was collected by a load cell synchronised with surface electromyography of masticatory muscles, bilaterally. RESULTS: Pain scores decreased for both groups, but the intervention group showed lower values at 8 weeks. No differences were noted between groups for PPT, but the results increased for both overtime. Time until fatigue and muscle efficiency were higher in the intervention group vs placebo group in both within- and between-subject analysis. Force increased from 4 to 8 weeks in the PG, without differences between groups. Temporal muscle excitation was higher on 8 weeks compared with baseline for the intervention group, without differences between groups. CONCLUSION: Eight-week exercise protocol of muscle endurance alleviates the pain and improves the resistance to fatigue and muscle efficiency in TMD subjects.