Center of Pressure Velocity and Dynamic Postural Control Strategies Vary During Y-Balance and Star Excursion Balance Testing.

Background: Dynamic postural control (DPC) describes an individual's ability to maintain balance within their base of support in both anticipatory and reactive balance situations and has been measured using center of pressure (COP) velocity. Common standardized DPC assessments for active adults include the modified Star Excursion Balance Test (MSEBT) and the Y-Balance Test (YBT). Hypothesis/Purpose: The purpose of this study was to explore DPC during performance of the MSEBT, the YBT, and a modified version of the YBT, the MYBT. It was hypothesized that feedback from the YBT/MYBT reach indicator would enhance DPC. Study Design: Cross-sectional study. Methods: Twenty-one participants (9 females, 12 males, mean age 24.5±1.2 years) performed three trials in each direction (anterior-AN, posteromedial-PM, and posterolateral-PL) on each balance test during one session. The YBT frame was placed atop a force plate for all testing. Frontal and sagittal plane COP velocities (COPx and COPy, respectively) were recorded throughout each trial and resultant COP (COPr) velocities were calculated. Results: Significant main effects were present for test (F=4.485, p\<0.001) and reach direction (F=61.594, p\<0.001). Post hoc analyses for test indicated significant differences in COPy between YBT and MSEBT (p=0.034) and between MYBT and MSEBT (p\<0.001), as well as significant differences in COPr between MYBT and MSEBT (p=0.002). Post hoc analyses for reach direction revealed significant differences in COPx between AN and both PM (p\<0.001) and PL (p\<0.001) directions, in COPy between AN and PM (p\<0.001) and PL (p\<0.001) directions, and COPr between AN and PL (p=0.043) directions only. Conclusion: External proprioceptive feedback from the reach indicator improved DPC during the YBT and MYBT when compared to the MSEBT. Sagittal plane COP velocities were reduced when external proprioceptive feedback from the reach indicator was present, while frontal plane COP velocities were not affected in this group of participants. Level of Evidence: 2b.

Match-Play External Load and Internal Load in NCAA Division II Women's Soccer.

ABSTRACT: Choice, EE, Tufano, JJ, Jagger, KL, and Cochrane-Snyman, KC. Match-play external load and internal load in NCAA Division II women's soccer. J Strength Cond Res 37(12): e633-e639, 2023-The purpose of this study was to describe average match-play demands for NCAA DII women's soccer, including positional and time-specific differences, and relationships between variables. External load was assessed using total distance, relative distance, sprint distance, number of power plays, peak speed, and Player Load. Internal load was assessed using session rating of perceived exertion (sRPE). Mixed factor analysis of variance was used to assess time by position (midfielder, forward, or defender) for dependent measures. Correlations were assessed between separate pair groups. Average match-play demands included 9,463 ± 2,591 m total distance, 172 ± 48 m·min -1 relative distance, 531 ± 301 m sprint distance, peak speeds of 26 ± 1.6 kph, 46.71 ± 21.75 power plays, and 457.84 ± 121.78 AU Player Load. Significant ( p < 0.05) positional differences were found for total distance, Player Load, match load, and peak speed. Significant, moderate correlations were found between relative distance and match load, and sRPE and total distance, Player Load, and power plays (all p < 0.001). Results indicate there are positional differences within a women's DII soccer team, with midfielders accumulating the longest distances (10,509 ± 2,913 m) and greatest Player Load (527.79 ± 130.5 AU) and match load (576 ± 343 AU), forwards running the fastest peak speeds (26.8 ± 1.5 kph), and defenders maintaining most consistent performance. Match-play external and internal load data should be monitored by player position and half for DII women's soccer.

Differences across Playing Levels for Match-Play Physical Demands in Women's Professional and Collegiate Soccer: A Narrative Review.

Advancements in sport technology have made quantifying match-play external load (e.g., total distance, sprint distance, number of sprints) a popular option for athletics personnel. These variables of volume and intensity are useful for both objectively monitoring training in field-based sports and for designing training programs. As physical abilities differ across playing levels, match-play demands likely also differ. This narrative review compiles and compares the match-play external load data for women's soccer at the professional and collegiate levels. Databases were searched through July 2022, yielding 13 primary articles that assessed the match-play demands of women's soccer (3 professional, 8 Division I, 1 Division II, and 1 Division III). The results indicate that the average total distance covered were similar between the professional, Division I and Division III levels, but the variability was greater among Division III compared to professional and Division I players. Data for Division II are scarce, but the total distance covered appears to be less than for professional, Division I and Division III. There was also large variability for sprint distance and number of sprints across data at all playing levels. Considering the lack of studies of Division II and Division III players, more research is necessary to determine how playing level may affect external load profiles, as isolated studies likely only reflect data from isolated teams.

A Comparison of Clinical Spinal Mobility Measures to Experimentally Derived Lumbar Spine Passive Stiffness.

Spinal stiffness and mobility assessments vary between clinical and research settings, potentially hindering the understanding and treatment of low back pain. A total of 71 healthy participants were evaluated using 2 clinical assessments (posteroanterior spring and passive intervertebral motion) and 2 quantitative measures: lumped mechanical stiffness of the lumbar spine and local tissue stiffness (lumbar erector spinae and supraspinous ligament) measured via myotonometry. The authors hypothesized that clinical, mechanical, and local tissue measures would be correlated, that clinical tests would not alter mechanical stiffness, and that males would demonstrate greater lumbar stiffness than females. Clinical, lumped mechanical, and tissue stiffness were not correlated; however, gradings from the posteroanterior spring and passive intervertebral motion tests were positively correlated with each other. Clinical assessments had no effect on lumped mechanical stiffness. The males had greater lumped mechanical and lumbar erector spinae stiffness compared with the females. The lack of correlation between clinical, tissue, and lumped mechanical measures of spinal stiffness indicates that the use of the term "stiffness" by clinicians may require reevaluation; clinicians should be confident that they are not altering mechanical stiffness of the spine through segmental mobility assessments; and greater resting lumbar erector stiffness in males suggests that sex should be considered in the assessment and treatment of the low back.

SCORING PERFORMANCE VARIATIONS BETWEEN THE Y-BALANCE TEST, A MODIFIED Y-BALANCE TEST, AND THE MODIFIED STAR EXCURSION BALANCE TEST.

BACKGROUND: The Modified Star Excursion Balance Test (MSEBT) and the Y-Balance Test- Lower Quarter (YBT-LQ) are utilized to assess dynamic postural stability. These assessments cannot be used interchangeably secondary to kinematic variations and performance differences. A Modified Y-Balance Test-Lower Quarter (MYBT-LQ) was developed to determine if a modification allows performance scores to be directly compared to the MSEBT. PURPOSE: The purpose of this research was to determine if reach distances were similar for young, healthy individuals between three different balance tests: the YBT-LQ, the MYBT-LQ, and the MSEBT. STUDY DESIGN: Repeated measures, descriptive cohort study. METHODS: Twenty-eight participants (17 males, 11 females) were recruited from a convenience sample of young, healthy adults. Participants completed all testing within a single session and performed three trials in each direction, on each leg, for all balance tests. Scoring performance was calculated for each balance test using the average normalized reach distance in the anterior, posterolateral, and posteromedial directions. A one-way ANOVA was used to compare between-subject posteromedial and posterolateral scores, while anterior scores were analyzed using a Kruskal Wallis test. The intraclass correlation coefficient (ICC) was used to determine within-subject participant performance reliability. RESULTS: Analyses indicated significant differences in the posterolateral and posteromedial reach directions between the YBT-LQ and MSEBT and between the MYBT-LQ and MSEBT, while no significant difference was found between the YBT-LQ and MYBT-LQ in any direction. No anterior reach differences were noted between any of the tests. Within-subject ICCs showed a very strong level of agreement between right and left anterior and right posteromedial reaches between all three tests, while only the YBT-LQ and MYBT-LQ demonstrated very strong agreement in all directions. CONCLUSION: Reach performance on the MSEBT differed from the performance on the YBT-LQ and MYBT-LQ in the anterior, posteromedial and posterolateral directions in this population. These findings further support the difference in motor control strategies used during these tests. LEVELS OF EVIDENCE: 2c.

A commentary review of the cost effectiveness of manual therapies for neck and low back pain.

BACKGROUND & PURPOSE: Neck and low back pain (NLBP) are global health problems, which diminish quality of life and consume vast economic resources. Cost effectiveness in healthcare is the minimal amount spent to obtain acceptable outcomes. Studies on manual therapies often fail to identify which manual therapy intervention or combinations with other interventions is the most cost effective. The purpose of this commentary is to sample the dialogue within the literature on the cost effectiveness of evidence-based manual therapies with a particular focus on the neck and low back regions. METHODS: This commentary identifies and presents the available literature on the cost effectiveness of manual therapies for NLBP. Key words searched were neck and low back pain, cost effectiveness, and manual therapy to select evidence-based articles. Eight articles were identified and presented for discussion. RESULTS: The lack of homogeneity, in the available literature, makes difficult any valid comparison among the various cost effectiveness studies. DISCUSSION: Potential outcome bias in each study is dependent upon the lens through which it is evaluated. If evaluated from a societal perspective, the conclusion slants toward "adequate" interventions in an effort to decrease costs rather than toward the most efficacious interventions with the best outcomes. When cost data are assessed according to a healthcare (or individual) perspective, greater value is placed on quality of life, the patient's beliefs, and the "willingness to pay."