The Acute Effects in Postural Sway as a Result of Self-Myofascial Release on the Lower Extremities in Collegiate Female Athletes.

Myofascial release is a popular therapy technique used to manipulate connective muscle tissue to become more pliable. The maintenance of body posture relies on mechanoreceptors located in connective tissue, thus manipulation of connective tissue should affect postural control. The effects of this phenomenon have not been well studied, leaving room for this investigation. PURPOSE: To observe if postural sway scores changed before and after foam rolling proximal (quadriceps and hamstrings) in comparison to distal (calves) muscles. METHODS: Thirty-six, college-aged female athletes (age 20.39 ± 0.25 years, mass 68.70 ± 1.97 kg, height 170.18 ± 1.56 cm.) performed approximately two and one-half minutes of moderate intensity foam rolling to their calves (n = 19, Group A) or to their hamstrings and quadricep muscle (n = 17, Group B). Center of Pressure (CoP) and Limit of Stability (LoS) testing was assessed both pre- and post-foam rolling using a computerized posturography balance plate. CoP sway was measured under both eyes open (EO) and eye closed (EC) Conditions on both stable and unstable surfaces. LoS was measured in the Anterior, Posterior, Left, and Right Directions. Effects of foam rolling on CoP and LoS were assessed using a repeated-measures MANOVA (α = 0.05). RESULTS: Eyes Open Stable Surface had the lowest postural sway (p = 0.001). However, CoP did not differ for any condition either between Groups (p ≥ 0.6) or from pre- to post-foam rolling (p = 0.3). LoS significantly differed between Directions such that LoS was greater in the frontal plane than in the sagittal plane (p = 0.011). There was also a significant Time X Group X Direction interaction effect (p = 0.001) such that LoS for Group A decreased after foam rolling (mean change = -1.621 cm) but increased for Group B after foam rolling (mean change = + 0.878 cm). No differences were found for any other Direction (p ≥ 0.1). CONCLUSION: This study demonstrated CoP and LoS improvements between the two groups based on acute effects of foam rolling intervention. Further research is suggested to determine if long-term gains are observed within or between groups.

Does a relationship between handgrip strength and coincidence anticipation timing exist among young adults: a pilot study.

The purpose of this investigation was to observe whether a strong to moderate relationship exists between maximal handgrip strength best score and best coincidence anticipation timing (CAT) score in young adults. Handgrip strength has demonstrated a strong relationship with high levels of activities of daily living (ADLs) and reduced injury potential. A one-shot case-study design was selected for this investigation. Twenty-three females and one male volunteered for this investigation (age 22.29 ± 4.71 years, height 63.78 ± 6.22 cm, mass 56.66 ± 8.25 kg) from a local higher education institution. Participants (n = 24) utilized the Bassin anticipation timing device (Lafayette Instruments, USA) and a Camry digital hand dynamometer (Model EH101, Camry LLC, El Monte, CA, USA) during the same time and recorded all scores. The Pearson correlation coefficient (r = -0.413; p = 0.04) indicated a medium effect relationship between best maximal handgrip strength and best CAT score.

Is There a Relationship Between Foot Reaction Time and Ankle Frontal Plane Torque in Female Soccer Athletes? A Pilot Study.

The purpose of this study was to determine if a relationship existed between foot reaction time and ankle frontal plane peak torque in female soccer athletes. A one-shot case study design was selected for this investigation. Seventeen female college athletes volunteered to participate. Right and left foot reaction time measurements were assessed using 3×4 switch mats interfaced with a precise timing counter. Participants stood in front of the mat with eyes closed and responded to the auditory stimulus by touching the mat as fast as possible with their foot. Two trials were conducted per foot, and the best time was used to determine the reaction time score per foot. An isokinetic dynamometer assessed inversion and eversion peak torque for both right and left ankle joint at 120°/sec. Left peak torque eversion and right foot reaction time demonstrated a significant negative moderate relationship (r = -0.530; p value = 0.03). Left ankle peak torque eversion does have a significant moderate negative relationship to reaction time of the right foot; therefore, evasive dribbling movements which requires inversion and eversion torque could directly affect foot reaction time, resulting in improved dribbling performance for soccer athletes.

Effects of a shoulder injury prevention strength training program on eccentric external rotator muscle strength and glenohumeral joint imbalance in female overhead activity athletes.

Imbalance of the eccentrically-activated external rotator cuff muscles versus the concentrically-activated internal rotator cuff muscles is a primary risk factor for glenohumeral joint injuries in overhead activity athletes. Nonisokinetic dynamometer based strength training studies, however, have focused exclusively on resulting concentric instead of applicable eccentric strength gains of the external rotator cuff muscles. Furthermore, previous strength training studies did not result in a reduction in glenoumeral joint muscle imbalance, thereby suggesting that currently used shoulder strength training programs do not effectively reduce the risk of shoulder injury to the overhead activity athlete. Two collegiate women tennis teams, consisting of 12 women, participated in this study throughout their preseason training. One team (n = 6) participated in a 5-week, 4 times a week, external shoulder rotator muscle strength training program next to their preseason tennis training. The other team (n = 6) participated in a comparable preseason tennis training program, but did not conduct any upper body strength training. Effects of this strength training program were evaluated by comparing pre- and posttraining data of 5 maximal eccentric external immediately followed by concentric internal contractions on a Kin-Com isokinetic dynamometer (Chattecx Corp., Hixson, Tennessee). Overall, the shoulder strength training program significantly increased eccentric external total work without significant effects on concentric internal total work, concentric internal mean peak force, or eccentric external mean peak force. In conclusion, by increasing the eccentric external total exercise capacity without a subsequent increase in the concentric internal total exercise capacity, this strength training program potentially decreases shoulder rotator muscle imbalances and the risk for shoulder injuries to overhead activity athletes.

Concentric internal and eccentric external fatigue resistanc of the shoulder rotator muscles in female tennis players.

BACKGROUND: Shoulder muscle imbalance is a potential shoulder injury risk factor in athletes performing overhead sports. While normative functional peak strength of concentric external to concentric internal shoulder muscle fatigue data is available, comparisons of functional eccentric external to concentric internal shoulder rotator muscle fatigue resistance, which impacts muscle imbalance throughout the duration of play, have not been studied in this population. OBJECTIVES: To assess fatigue resistance of the internal and external shoulder rotator muscles in female tennis players. METHODS: Fifteen female collegiate tennis players were tested bilaterally for shoulder concentric internal and eccentric external peak torque production throughout 20 maximal repetitions on a Kin-Com isokinetic dynamometer. Twelve t - tests were conducted to evaluate for differences in peak torque, relative fatigue ratios, and functional peak torque ratios between extremities and mode of activation during the first, as well as, last five repetitions that were conducted. RESULTS: Non-dominant concentric internal and eccentric external peak torque production significantly decreased throughout the twenty repetitions. Neither dominant concentric internal peak torque decrements and eccentric peak torque decrements were not significantly different across the twenty contractions. These changes in peak torque upon subsequent repetitions resulted in relative fatigue ratios of dominant eccentric external rotation that were significantly greater than non-dominant eccentric external rotation. Relative fatigue ratios of dominant concentric internal rotation did not differ from non-dominant concentric internal rotation. CONCLUSIONS: The data suggest that eccentrically activated external shoulder rotator muscles could possibly adapt to overhead activities by becoming more fatigue resistant.