Leg and Joint Stiffness of the Supporting Leg during Side-Foot Kicking in Soccer Players with Chronic Ankle Instability.

Soccer players with chronic ankle instability (CAI) may stabilize their supporting leg by the proximal joint to compensate for the ankle instability during kicking motion. This study aimed to investigate the characteristics of leg and joint stiffness of the supporting leg during side-foot kicking in soccer players with CAI. Twenty-four male collegiate-level soccer players with and without CAI participated in this study. The kinematic and kinetic data were obtained using a three-dimensional motion analysis system. Leg stiffness and joint (hip, knee, and ankle) stiffness in the sagittal and frontal planes were calculated and analyzed. The results clarified that soccer players with CAI (0.106 ± 0.053 Nm/°) had greater knee stiffness in knee adduction during the kicking cycle compared to those without CAI (0.066 ± 0.030 Nm/°; p = 0.046), whereas no characteristic differences were observed in knee stiffness in knee flexion and hip and ankle stiffness (p > 0.05). Knee stiffness is believed to occur to compensate for ankle joint instability in the supporting leg. Therefore, adjusting knee stiffness to accommodate ankle joint instability is crucial for maintaining kicking performance. Based on results of this study, it may be important to consider training and exercises focused on joint coordination to improve knee stiffness in soccer players with CAI.

Biomechanical Characteristics of the Support Leg During Side-Foot Kicking in Soccer Players With Chronic Ankle Instability.

Background: Chronic ankle instability (CAI) in soccer players can increase the risk of recurrent ankle varus sprains and damage the articular surface of the ankle joint, thus increasing the risk of osteoarthritis. It is important to understand the biomechanical characteristics of the support leg during kicking in soccer players with CAI. Purpose/Hypothesis: The purpose of this study was to clarify the kinematics of the kicking motion of soccer players with CAI. It was hypothesized that at the point before ball contact when the support leg makes flat-foot contact with the ground, soccer players with CAI will land with ankle inversion in the support leg during a side-foot kick compared with players without CAI. Study Design: Controlled laboratory study. Methods: The study cohort included 19 male college soccer players (mean age, 20.5 ± 0.9 years) with greater than 8 years of soccer experience who were recruited from August 2019 to March 2020. Of these athletes, 10 had CAI and 9 had no CAI in the support leg, as diagnosed according to the Cumberland Ankle Instability Tool. Kinematic data for the trunk, hip, knee, and foot of the support leg during a side-foot kick were obtained using a 3-dimensional, motion-analysis system. The Mann-Whitney U test or Student t test was selected to identify differences in variables between the CAI and non-CAI groups. Results: There were no significant differences in physical characteristics between the CAI and non-CAI groups. At the point when the support leg made flat-foot contact with the ground, the players with CAI had more eversion of the hindfoot with respect to the tibia (-28.3° ± 12.1° vs -13.9° ± 14.2°; P = .03), a more varus alignment of the knee (26.0° ± 10.7° vs 13.7° ± 10.5°; P = .03), and a lower arch height index (0.210 ± 0.161 vs 0.233 ± 0.214; P = .046) compared with non-CAI players. Conclusion: Significant differences between players with and without CAI were seen in the support leg kinematics at flat-foot contact with the ground during the kicking cycle. Clinical Relevance: The biomechanical alignment of the support leg during a side-foot kick in players with CAI may reflect a subconscious attempt to avoid inversion of the foot and further ankle sprains.

Physique, range of motion, and gross muscle strength in hemiplegic para swimmers: a cross-sectional case series.

[Purpose] The physical functions related to swimming should be evaluated to enhance competitive performance and prevent sports injuries. This study aimed to determine the physique, range of motion, and gross muscle strength of the limbs among hemiplegic para swimmers. [Participants and Methods] Three male para swimmers with hemiplegia and five male para swimmers with impaired vision were included in the study. The limb circumference, range of motion, quadriceps flexibility, and gross muscle strength were evaluated. The hemiplegic swimmers and swimmers with impaired vision were compared using an unpaired t-test. [Results] The maximum values of the upper and forearm circumferences; the range of motion for shoulder flexion, external rotation, ankle dorsiflexion on the paretic side; and the single-leg sit-to-stand test of the dominant limb were significantly lower in hemiplegic swimmers than in swimmers with impaired vision. [Conclusion] Hemiplegic swimmers had decreased upper limb circumferences on the paretic limb; the range of motion for shoulder flexion, external rotation, and ankle dorsiflexion on the paretic limb; and muscle strength on the dominant lower limb.

A survey of health awareness and physical activity among Japanese undergraduate rehabilitation students.

[Purpose] We aimed to investigate students' awareness of their general physical activity and current physical activity habits. [Participants and Methods] One hundred and eighteen undergraduate students in rehabilitation courses volunteered to participate in this survey. The participants were required to answer a questionnaire related to their health awareness and physical activity habits. A χ2 test was used to demonstrate the relationships between each category of the selected items. [Results] Undergraduate rehabilitation students felt very or moderately healthy when asked to subjectively describe the current condition of their health. Most of them liked and had more interest in exercise or sports activities. However, more than 60% of them felt that their participation in physical activities had decreased since they entered college. [Conclusion] Undergraduate students in rehabilitation courses lacked motivation to exercise and participate in physical activities in college. Students who did not have a habit of exercising or participating in sports activities may have lacked motivation because they were busy with school; however, they had a high level of positivity towards exercise or sports activities. Therefore, it is important for them to actively participate in exercise and/or physical activity with a specific purpose in mind.

Characteristics of age-related changes in blood pressure, oxyhemoglobin saturation, and physique in Bolivians residing at different altitudes: presentation of basic data for health promotion.

[Purpose] To present basic data for a health promotion plan tailored to the body function of Bolivians residing in different municipalities and altitudes by investigating their blood pressure and oxyhemoglobin saturation. [Participants and Methods] The participants were 589 Bolivians residing in different altitudes who voluntarily participated in health promotion activities. We measured the blood pressure, peripheral capillary oxygen saturation, height, and weight, and calculated the body mass index. We divided the participants into two groups based on the altitude (valley and lowland) and the participants of each altitude group into six age brackets (every 10 years) to investigate the effect of age on each value. [Results] The altitude affected the systolic and diastolic blood pressure, oxyhemoglobin saturation, and height. All average values in the valley group were lower than those in the lowland group. There were significant effects in all variables based on age. The body mass index values were significantly higher in participants aged 45-64 years compared to those aged 18-34 years; the average value was 29. [Conclusion] An anti-obesity initiative for health promotion is needed to reduce the risk of health impairment in Bolivians, especially lifestyle-related diseases, such as type 2 diabetes mellitus, cardiovascular diseases, and stroke.

Effect of increased functional residual capacity on the active range of thoracic axial rotation in healthy young men.

[Purpose] To understand the effect of increased functional residual capacity (FRC) on the active range of thoracic axial rotation (AROTAR) in healthy young men. [Subjects and Methods] Thirty-nine right-handed healthy male volunteers (age=20.1 ± 1.6 years) participated in this study. A standard plastic goniometer was used to measure the AROTAR in the supine position with both glenohumeral joints fully flexed. AROTAR was recorded at the resting expiration level (REL) and for 4 different FRC levels: 500, 1,000, 1,500, and 2,000 ml air inhaled at REL. FRC volumes and laterality were analyzed using a two-way repeated measure of ANOVA and post-hoc analysis. Relationships between the relative value (AROTAR for each increased FRC level / REL AROTAR × 100) and AROTAR for each increased FRC level were analyzed using Pearson's correlation coefficient. [Results] A significant main effect was found for only FRC factor. AROTAR had a positive moderate correlation with relative value. The correlation coefficient was higher than 0.5 for in 1,500 and 2,000 ml. [Conclusion] An increase in FRC might decrease AROTAR and if the REL AROTAR is high, the decrease in AROTAR due to increased FRC is lesser. It is suggested that maintaining the thoracic mobility could minimize a COPD patient's AROTAR limitation and maintain physical ability.