Differences and relationships between weightbearing and non-weightbearing dorsiflexion range of motion in foot and ankle injuries.

BACKGROUND: This study aimed to: (1) identify assessment methods that can detect greater ankle dorsiflexion range of motion (DROM) limitation in the injured limb; (2) determine whether differences in weightbearing measurements exist even in the absence of DROM limitations in the injured limb according to non-weightbearing measurements; and (3) examine associations between DROM in the weightbearing and non-weightbearing positions and compare those between a patient group with foot and ankle injuries and a healthy group. METHODS: Eighty-two patients with foot and ankle injuries (e.g., fractures, ligament and tendon injuries) and 49 healthy individuals participated in this study. Non-weightbearing DROM was measured under two different conditions: prone position with knee extended and prone position with knee flexed. Weightbearing DROM was measured as the tibia inclination angle (weightbearing angle) and distance between the big toe and wall (weightbearing distance) at maximum dorsiflexion. The effects of side (injured, uninjured) and measurement method on DROM in the patient groups were assessed using two-way repeated-measures ANOVA and t-tests. Pearson correlations between measurements were assessed. In addition, we analyzed whether patients without non-weightbearing DROM limitation (≤ 3 degrees) showed limitations in weightbearing DROM using t-tests with Bonferroni correction. RESULTS: DROM in patient groups differed significantly between legs with all measurement methods (all: P < 0.001), with the largest effect size for weightbearing angle (d = 0.95). Patients without non-weightbearing DROM limitation (n = 37) displayed significantly smaller weightbearing angle and weightbearing distance on the injured side than on the uninjured side (P < 0.001 each), with large effect sizes (d = 0.97-1.06). Correlation coefficients between DROM in non-weightbearing and weightbearing positions were very weak (R = 0.17, P = 0.123) to moderate (R = 0.26-0.49, P < 0.05) for the patient group, and moderate to strong for the healthy group (R = 0.51-0.69, P < 0.05). CONCLUSIONS: DROM limitations due to foot and ankle injuries may be overlooked if measurements are only taken in the non-weightbearing position and should also be measured in the weightbearing position. Furthermore, DROM measurements in non-weightbearing and weightbearing positions may assess different characteristics, particularly in patient group. LEVEL OF EVIDENCE: Level IV, cross-sectional study.

Point Prevalence of the Biomechanical Dimension of Dysfunctional Breathing Patterns Among Competitive Athletes.

ABSTRACT: Shimozawa, Y, Kurihara, T, Kusagawa, Y, Hori, M, Numasawa, S, Sugiyama, T, Tanaka, T, Suga, T, Terada, RS, Isaka, T, and Terada, M. Point prevalence of the biomechanical dimension of dysfunctional breathing patterns among competitive athletes. J Strength Cond Res 37(2): 270-276, 2023-There is growing evidence of associations between altered biomechanical breathing patterns and numerous musculoskeletal and psychological conditions. The prevalence of dysfunctional and diaphragmatic breathing patterns is unknown among athletic populations. The purpose of this study was to examine the prevalence of dysfunctional and diaphragmatic breathing patterns among athletic populations with a clinical measure to assess the biomechanical dimension of breathing patterns. Using a cross-sectional design, 1,933 athletes across multiple sports and ages were screened from 2017 to 2020. Breathing patterns were assessed using the Hi-Lo test in the standing position. Scores of the Hi-Lo test were determined based on the presence or absence of abdominal excursion, anterior-posterior chest expansion, superior rib cage migration, and shoulder elevation. The Hi-Lo test scores were used to categorize observational breathing mechanics as dysfunctional and diaphragmatic breathing patterns. The prevalence of athletes with dysfunctional breathing patterns was 90.6% (1,751 of 1,933). Athletes with diaphragmatic breathing patterns accounted for 9.4% of all athletes in our sample (182 of 1,933). There were no differences in the proportion of breathing patterns between male and female athletes ( p = 0.424). Breathing patterns observations were associated with sport-setting categories ( p = 0.002). The highest percentages of dysfunctional breathers were in middle school student athletes (93.7%), followed by elementary school student athletes (91.2%), high school student athletes (90.6%), professional/semiprofessional athletes (87.5%), and collegiate athletes (84.8%). The current study observed that dysfunctional breathing patterns (90.6%) in the biomechanical dimension were more prevalent than diaphragmatic breathing pattern (9.4%) among competitive athletes. These results suggest that clinicians may need to consider screening breathing patterns and implementing intervention programs aimed to improve the efficiency of biomechanical dimensions of breathing patterns in athletic populations. This study may help raise awareness of impacts of dysfunctional breathing patterns on athletes' health and performance.

Effects of age and sex on association between toe muscular strength and vertical jump performance in adolescent populations.

Toe muscular strength plays an important role in enhancing athletic performance because the forefoot is the only part of the body touching the ground. In general, muscular strength increases with age throughout adolescence, and sex-related difference in muscular strength becomes evident during childhood and adolescence. However, toe muscular strength is known to be levelled off after late adolescence in both sexes. For adolescent populations, therefore, the association of toe muscular strength with physical performance might differ with age and/or sex. This study aimed to investigate differences in relationships between toe muscular strength and vertical jump performance across sex and age in adolescent populations. The maximum isometric strength of the toe muscles and vertical jump height (VJ) were assessed in 479 junior high school students (JH) aged 12-14 years (243 boys and 236 girls) and 465 high school students (HS) aged 15-18 years (265 boys and 200 girls). Two types of measurements were performed to evaluate the toe muscular strength: toe gripping strength (TGS) with the metatarsophalangeal joint in the plantar flexed position and toe push strength (TPS) with the metatarsophalangeal joint in the dorsiflexed position. TGS and TPS were normalized to body weight. Two-way ANOVA showed that TGS had significant main effects of sex (boys > girls) and age (HS > JH) while TPS only had a significant main effect of sex (boys > girls). When the effects of sex and age were separately analyzed, VJ was significantly correlated with TGS in JH girls, HS girls, and JH boys (r = 0.253-0.269, p < 0.05), but not in HS boys (r = 0.062, p = 0.3351). These results suggest that toe muscular strength is relatively weakly associated with vertical jump performance in adolescent boys and girls, but the association would not be established in high school boys.