Centre of pressure velocity shows impairments in NCAA Division I athletes six months post-concussion during standing balance

Evaluating the effect of sports compression tights on balance, sprinting, jumping and change of direction tasks

Compression garments are commonly used during athletic tasks. However, the effect of compression garments on balance, sprinting, jumping and change of direction performance requires further investigation. In the current study, 24 recreationally active participants (12 males, 12 females, age 27 ± 3 years) completed single-leg balance tasks, countermovement jumps, drop jumps, 10 m straight line sprints and change of direction tasks wearing either compression tights (COMP) or regular exercise tights (CON). There was a significant main effect of the condition for 10 m sprint time (p = 0.03, d = -0.18) and change of direction time (p = 0.03, d = -0.20) in favour of COMP. In addition, there was a significant, small difference (p = 0.05, d = -0.30) in ellipse area and a small (p = 0.16, d = 0.21) difference in balance time in favour of COMP during a single-leg balance task. There were no significant differences between trials for any of the other balance or jump tests (p > 0.05). The application of compression tights during exercise may offer small benefits to the performance of balance and change of direction tasks, though these benefits are likely within the typical error of measurement for the tests used.

Validity and Reliability of Methods to Assess Movement Deficiencies Following Concussion: A COSMIN Systematic Review

BACKGROUND

There is an increased risk of subsequent concussion and musculoskeletal injury upon return to play following a sports-related concussion. Whilst there are numerous assessments available for clinicians for diagnosis and during return to play following concussion, many may lack the ability to detect these subclinical changes in function. Currently, there is no consensus or collated sources on the reliability, validity and feasibility of these assessments, which makes it difficult for clinicians and practitioners to select the most appropriate assessment for their needs.

OBJECTIVES

This systematic review aims to (1) consolidate the reliability and validity of motor function assessments across the time course of concussion management and (2) summarise their feasibility for clinicians and other end-users.

METHODS

A systematic search of five databases was conducted. Eligible studies were: (1) original research; (2) full-text English language; (3) peer-reviewed with level III evidence or higher; (4) assessed the validity of lower-limb motor assessments used to diagnose or determine readiness for athletes or military personnel who had sustained a concussion or; (5) assessed the test-retest reliability of lower-limb motor assessments used for concussion management amongst healthy athletes. Acceptable lower-limb motor assessments were dichotomised into instrumented and non-instrumented and then classified into static (stable around a fixed point), dynamic (movement around a fixed point), gait, and other categories. Each study was assessed using the COSMIN checklist to establish methodological and measurement quality.

RESULTS

A total of 1270 records were identified, with 637 duplicates removed. Titles and abstracts of 633 records were analysed, with 158 being retained for full-text review. A total of 67 records were included in this review; 37 records assessed reliability, and 35 records assessed the validity of lower-limb motor assessments. There were 42 different assessments included in the review, with 43% being non-instrumented, subjective assessments. Consistent evidence supported the use of instrumented assessments over non-instrumented, with gait-based assessments demonstrating sufficient reliability and validity compared to static or dynamic assessments.

CONCLUSION

These findings suggest that instrumented, gait-based assessments should be prioritised over static or dynamic balance assessments. The use of laboratory equipment (i.e. 3D motion capture, pressure sensitive walkways) on average exhibited sufficient reliability and validity, yet demonstrate poor feasibility. Further high-quality studies evaluating the reliability and validity of more readily available devices (i.e. inertial measurement units) are needed to fill the gap in current concussion management protocols. Practitioners can use this resource to understand the accuracy and precision of the assessments they have at their disposal to make informed decisions regarding the management of concussion.

TRAIL REGISTRATION

This systematic review was registered on PROSPERO (reg no. CRD42021256298).

Characteristics of the postural stability of the lower limb in different visual states of undergraduate students with moderate myopia

Objective: To explore the characteristics of lower limb postural stability in undergraduates with moderate myopia in three different visual states. Methods: Twenty male undergraduate students were recruited to complete respectively the static and dynamic postural stability tests under eyes-closed, myopia (taking off their glasses immediately) and corrected vision conditions. A three-dimensional force platform (Bertec, United States) was used to test static postural stability, which calculated the total path length of the Center of Pressure (COP), path length in the antero-posterior (A/P) and medio-lateral (M/L) directions, COP area, SampleEntropy (SampEn), and low-, medium-, and high-frequency spectrum energies. Dynamic postural stability was tested using the Y-balance test, and the Y-balance test scores were calculated. The Vicon three-dimensional motion capture system (Oxford, United Kingdom) measured the maximum flexion angles of the ankle, knee, and hip joints. The electromyography (EMG) root mean square (RMS) and integral EMG (iEMG) of the tibialis anterior and lateral gastrocnemius of the lower extremity were simultaneously measured using wireless surface electromyography (Noraxon, United States). Results: The SampEn-A/P and SampEn-M/L of corrected vision state higher than myopia and eyes-closed states, and myopia state larger than eyes-closed state (χ² = 51.631, p < .001). The original and standard scores of the anterior, postero-medial and comprehensive values of the three visual states had significant differences (F = 32.125, p < .001). The original and standard values of postero-lateral corrected vision and myopia were larger than those of eyes-closed states (F = 37.972, p < .001). The maximum flexion angles of the ankle and knee joints were in the following order: corrected vision, myopia and eyes-closed (F = 10.93, p < .001). The iEMG and RMS had significant differences in the three different states (χ² = 12.700, p < .001) in the all directions of YBT. Conclusion: Compared with corrected vision, the stability of static posture in the state of myopia was decreased, and the postural regularity was more regular. The dynamic postural stability in the state of myopia was also lower than that corrected vision, and the activation and work of ankle muscles were also increased.