Carbon Fiber Insoles Enhance Perception of Performance Despite Variable Objective Outcomes: Specific to the Moderately Active Individual.

Carbon fiber insoles (CFIs) may benefit performance in elite athletes, however, their use in moderately active individuals has been adopted without evidence supporting such enhancements in this population. Fifteen male subjects performed vertical jump (VJ) and repeat treadmill sprint tests before and after a VO2peak while wearing 1) CFIs and 2) control insoles (CON). Subjects completed a subjective survey regarding their perceived performance abilities for both conditions. There were no significant differences between CFIs and CON in VJ height, sprint distance, heart rate following sprints; and rate of oxygen consumption, perceived fatigue, and perceived exertion at 85% of maximal speed (p > 0.05) during the VO2peak. At maximal speed, although there was no difference between conditions in peak rate of oxygen consumption (95%CI [-4.85, 0.21]) and respiratory exchange ratio (95%CI [-0.01, 0.03]), CFIs resulted in a reduced level of perceived fatigue (95%CI [-1, 0]) and perceived exertion (95%CI [-2, 0]) compared to CON. Subjects subjectively reported increased feelings of "propulsion or explosiveness" (p = 0.026) and being able to "perform better while jumping" (p = 0.029) while wearing CFIs. Heightened perceptions of performance enhancements when wearing CFIs indicate, in the moderately active, perceptual benefits could be more influential for determining CFI use.

The Comparison of Psychological Barriers Between Individuals with a History of Anterior Knee Pain, Anterior Cruciate Ligament Reconstruction, and Healthy Individuals.

Background: Psychological barriers due to anterior knee pain (AKP) and anterior cruciate ligament reconstruction (ACLR) may have a direct impact on an individual's return to physical activity. A comprehensive understanding of these psychological barriers in individuals with AKP and ACLR may help clinicians to develop and implement better treatment strategies to address deficits that may exist in these individuals. Hypothesis/Purpose: The primary purpose of this study was to evaluate fear-avoidance, kinesiophobia, and pain catastrophizing in individuals with AKP and ACLR compared with healthy individuals. The secondary purpose was to directly compare psychological characteristics between the AKP and ACLR groups. It was hypothesized that 1) individuals with AKP and ACLR would self-report worse psychosocial function than healthy individuals and 2) the extent of the psychosocial impairments between the two knee pathologies would be similar. Study Design: Cross-sectional study. Methods: Eighty-three participants (28 AKP, 26 ACLR, and 29 healthy individuals) were analyzed in this study. Fear avoidance belief questionnaire (FABQ) with the physical activity (FABQ-PA) and sport (FABQ-S) subscales, Tampa scale of Kinesiophobia (TSK-11) and pain catastrophizing scale (PCS) assessed psychological characteristics. Kruskal-Wallis tests were used to compare the FABQ-PA, FABQ-S, TSK-11, and PCS scores across the three groups. Mann-Whitney U tests were performed to determine where group differences occurred. Effect sizes (ES) were calculated with the Mann-Whitney U z-score divided by the square root of the sample size. Results: Individuals with AKP or ACLR had significantly worse psychological barriers compared to the healthy individuals for all questionnaires (FABQ-PA, FABQ-S, TSK-11, and PCS) (p<0.001, ES>0.86). There were no differences between the AKP and ACLR groups (p≥0.67), with a medium ES (-0.33) in the FABQ-S between AKP and ACLR groups. Conclusion: Greater psychological scores indicate impaired psychological readiness to perform physical activity. Clinicians should be aware of fear-related beliefs following knee-related injuries and are encouraged to measure psychological factors during the rehabilitation process. Level of Evidence: 2.

Youth Perceptions of Sport-Confidence.

ABSTRACT: Zuk, EF, Maksymiw, K, Evanovich, J, McGarry, JE, Root, HJ, and Distefano, LJ. Youth perceptions in sport-confidence. J Strength Cond Res 35(11): 3232-3235, 2021-Sport-confidence is an important construct that is often missed during physical activity interventions in youth. Male and female children might display differences in sport-confidence that influences their activity levels. The purpose of this study is to assess any association between sport-confidence and gender in elementary school and middle-school children. All 286 children {(boys [ES: n = 71, age = 8±1 years; MS: n = 63, 11±1 years]; girls [ES: n = 67, 7±1 years; MS: n = 85, 11±1 years])} completed the Physical Literacy Assessment for Youth-Self Questionnaire. Separate chi-square tests of the association were used to evaluate the association between gender and sport-confidence among elementary (grades K-4) and middle-school (grades 5-8) children because of varying injury and participation rates for these groups, for each relevant question with a significance set at p ≤ 0.05. For elementary school children, there were no significant associations between genders and sport-confidence (p > 0.05). In middle-school children, there were significant associations detected for learning new skills (ϕ = 0.12; p = 0.031), perception of skill (ϕ = 0.12; p = 0.054), confidence in activity (ϕ = 0.17; p = 0.035), and being the best in the class (ϕ = 0.15; p = 0.048) between genders and sport-confidence. For all results, boys displayed more sport-confidence than girls. Education for key stakeholders about the importance of including sport-confidence in physical activity interventions is integral in promoting life-long activity, specifically in middle-school girls.

The impact of body fat on thermoregulation during exercise in the heat: A systematic review and meta-analysis.

OBJECTIVES: We performed a systematic review and meta-analysis to examine the effect of body fat on thermoregulatory responses to exercise in the heat. DESIGN: Systematic Review and Meta-analysis. METHODS: We systematically searched databases (N = 8) for studies that included: healthy participants; an aerobic exercise intervention under heat stress; a measure of body fat by a high and low body fat group; pre- and post-exercise internal temperature, and/or post-exercise mean skin temperature and whole body sweat loss. Criteria to distinguish high body fat and low body fat were determined by each qualifying study. Out of 1222 potential studies, 10 qualified. Robust variance estimation models were utilized to determine the pooled effect size (ES, 95% CI) for interventions that performed unbias comparisons between groups. RESULTS: Participants (n = 211) were mostly male (70%) and young (19.3 ±â€¯7.1 years) with a maximal oxygen consumption of 50.42 ±â€¯9.3 ml∙kg-1∙min-1 by high body fat (36.7 ±â€¯11.8%) and low body fat (17.8 ±â€¯5.7%). Exercise duration was between 30 and 60 min at moderate-high intensity (44.1-71.4% VO2max) at 28-40.3 °C and 26-50% humidity. Of the 7 interventions that normalized metabolic heat production to body mass and 5 interventions that normalized to external workload, there were no differences in any of the three outcome variables between groups. CONCLUSIONS: Many of the included studies did not control for confounding factors that may affect the relationship between body fat and thermoregulation during exercise in the heat such as metabolic heat production and body mass. Given the small number of interventions included, future work must make unbiased comparisons to appropriately assess the independent influence of body fat.

The Utilization of Core Exercises in Patients With Patellofemoral Pain: A Critically Appraised Topic.

Clinical Scenario: Patellofemoral pain (PFP) is characterized by general anterior knee pain around the patella and is one of the most prevalent knee conditions. PFP is challenging to treat due to a wide range of contributing factors and often has chronic, reoccurring symptoms. Traditional treatment focuses on quadriceps and gluteal strengthening with minimal emphasis on deep trunk musculature. Recently, there has been a growing body of literature supporting the beneficial effects of core stability exercises as a treatment option for PFP. Clinical Question: Are core stability exercises coupled with traditional rehabilitation more effective than only traditional rehabilitation techniques for decreasing pain in patients with PFP? Summary of Key Findings: Three articles met the inclusion criteria and investigated core strengthening exercises as a treatment for PFP. Two studies investigated a 4-week exercise protocol and demonstrated a greater decrease in pain when compared to the control group. The third study examined the effects of a 6-week program where both the intervention and control groups resulted in similar reduction of pain. All articles included received a minimum of 6 on the PEDro scale. Clinical Bottom Line: There is evidence that supports core stability exercise protocols coupled with traditional rehabilitation as being more effective in reducing pain in patients with PFP when compared to traditional rehabilitation alone. Strength of Recommendation: The grade of A is recommended based on the Strength of Recommendation Taxonomy.

MODIFYING MIDSOLE STIFFNESS of BASKETBALL FOOTWEAR AFFECTS FOOT and ANKLE BIOMECHANICS.

BACKGROUND: There is a growing incidence of foot injuries in basketball, which may be from the sport's repetitive, forceful multi-directional demands. Modifying midsole stiffness of the basketball shoe has been reported to alter ankle motion and plantar forces to reduce the risk of injury; however, the effects on anatomical, in-shoe foot (metatarsal), motion is not well understood. PURPOSE: The purpose of this study was to identify differences in foot and ankle biomechanics between basketball shoes with differing midsole stiffness values during single-leg jump landings. It was hypothesized that a stiffer midsole would elicit lower 1st metatarsophalangeal joint (MTPJ) dorsiflexion angles, higher ankle dorsiflexion angles, and higher plantar forces and relative loading in the distal foot. STUDY DESIGN: Experimental cross-sectional study. METHODS: Twenty high school and collegiate-aged basketball players performed a single-leg side drop jump and a single-leg cross drop jump in a pair of standard basketball shoes and a pair of shoes modified with a fiberglass plate to increase midsole stiffness. Three-dimensional motion analysis and flexible insoles quantified foot and ankle kinematics and plantar force distribution, respectively. Separate 2 (footwear) × 2 (task) repeated measures ANOVA models were used to analyze differences in 1) ankle kinematics, 2) 1st metatarsophalangeal kinematics, 3) maximal regional plantar forces, and 4) relative load. RESULTS: The stiffer shoe elicited decreased peak ankle plantarflexion (mean difference = 5.8 °, p = 0.01) and eversion (mean difference = 6.6 °, p = 0.03) and increased peak ankle dorsiflexion angles (mean difference = 5.0 °, p = 0.008) but no differences were observed in 1st MTPJ motion (p > 0.05). The stiffer shoe also resulted in lower peak plantar forces (mean difference = 24.2N, p = 0.004) and relative load (mean difference = 1.9%, p = 0.001) under the lesser toes. CONCLUSIONS: Altering the midsole stiffness in basketball shoes did not reduce motion at the MTPJ, indicating that added stiffness may reduce shoe motion, but does not reduce in-shoe anatomical motion. Instead, a stiffer midsole elicits other changes, including additional ankle joint motion and a reduction in plantar forces under the lesser toes. Collectively, this indicates that clinicians need to account for unintended compensations that can occur throughout the kinetic chain when altering a shoe property to alleviate a musculoskeletal injury. LEVEL OF EVIDENCE: 2b.

Longitudinal Changes in Hip Strength and Range of Motion in Female Youth Soccer Players: Implications for ACL Injury, A Pilot Study.

CONTEXT: Risk of anterior cruciate ligament (ACL) injuries in young female athletes increases with age, appearing to peak during maturation. Changes in hip muscle strength and range of motion (ROM) during this time may contribute to altered dynamic movement patterns that are known to increase risk of ACL injuries. Understanding the longitudinal changes in hip strength and ROM is needed to develop appropriate interventions to reduce the risk of ACL injuries. OBJECTIVE: To examine the longitudinal changes in hip strength and ROM in female youth soccer players. DESIGN: Longitudinal descriptive study. SETTING: Field setting. PARTICIPANTS: 14 female youth soccer athletes (14.1 ± 1.1 y, 165.8 ± 5.3 cm, 57.5 ± 9.9 kg) volunteered as part of a multiyear risk factor screening project. MAIN OUTCOME MEASURES: Clinical measures of hip strength and ROM were collected annually over 3 consecutive years. Passive hip internal rotation (IR), external rotation (ER), abduction (ABD), and adduction (ADD) ROM were measured with a digital inclinometer. Isometric hip ABD and extension (EXT) strength were evaluated using a hand-held dynamometer. Separate repeated-measures ANOVAs compared hip strength and ROM values across 3 consecutive years (P < .05). RESULTS: As youth female soccer players increased in age, there were no changes in normalized hip ABD (P = .830) or EXT strength (P = .062) across 3 consecutive years. Longitudinal changes in hip ROM were observed with increases in hip IR (P = .001) and ABD (P < .001), while hip ADD (P = .009) and ER (P < .001) decreased. CONCLUSIONS: Anatomical changes at the hip occur as youth female soccer players increase in age. While there are no changes in hip strength, there is an increase in hip IR and ABD ROM with a concomitant decrease in hip ER and ADD ROM. The resulting asymmetries in hip ROM may decrease the activation and force producing capabilities of the hip muscles during dynamic activities, contributing to altered lower extremity mechanics known to increase the risk of ACL injuries.

An evidence-based review of hip-focused neuromuscular exercise interventions to address dynamic lower extremity valgus.

Deficits in proximal hip strength or neuromuscular control may lead to dynamic lower extremity valgus. Measures of dynamic lower extremity valgus have been previously shown to relate to increased risk of several knee pathologies, specifically anterior cruciate ligament ruptures and patellofemoral pain. Therefore, hip-focused interventions have gained considerable attention and been successful in addressing these knee pathologies. The purpose of the review was to identify and discuss hip-focused exercise interventions that aim to address dynamic lower extremity valgus. Previous electromyography, kinematics, and kinetics research support the use of targeted hip exercises with non-weight-bearing, controlled weight-bearing, functional exercise, and, to a lesser extent, dynamic exercises in reducing dynamic lower extremity valgus. Further studies should be developed to identify and understand the mechanistic relationship between optimized biomechanics during sports and hip-focused neuromuscular exercise interventions.