Comparison of the distance between the talus and lateral malleolus during the stance phase with and without chronic ankle instability.

The level of dynamic mechanical instability between the bony parts of the ankle joint provides important information on biomechanical function. However, the dynamics of the distance between the talus and lateral malleolus during gait remain unclear. This study aimed to compare the distance between the talus and lateral malleolus and the ankle joint angles during the stance phase of gait between individuals with chronic ankle instability (CAI) and healthy adults.

The vertical mobility of the first tarsometatarsal joint during demi-plié with forced turnout in ballet dancers.

The forced turnout has a perceived risk of development of hallux valgus (HV) in ballet dancers. We determined how the forced turnout affects the sagittal mobility of the first tarsometatarsal (TMT) joint, which is one of the pathogenic factors of HV development. Seventeen female ballet dancers (body mass index: 18.

Head impact differences in blind football between Rio 2016 and Tokyo 2020 Paralympic Games: video-based observational study.

Objective: In Tokyo 2020 Paralympic Games, there were the rule and goal size changes at the blind football competition. This study aimed to compare the scoring and head impact characteristics during blind football competition between the Rio 2016 and Tokyo 2020 Paralympic Games using the official videos.

Design: Video-based observational study.

Relationship of Chronic Ankle Instability With Foot Alignment and Dynamic Postural Stability in Adolescent Competitive Athletes.

Background: Competitive adolescent athletes should be aware of the early signs of chronic ankle instability (CAI) and the connection between the condition and performance.

Purpose: To investigate whether CAI is related to foot alignment and morphology as well as dynamic postural stability after a jump landing among adolescent competitive athletes with and without a history of a lateral ankle sprain and CAI.

Study Design: Cross-sectional study; Level of evidence, 3.

Effect of postural differences on the activation of intrinsic foot muscles during ramp-up toe flexion in young men.

Background: Intrinsic foot muscle exercises are used in clinical and sports practice to improve performance. Force generation during toe flexion is greater in the standing posture than in the sitting posture; nonetheless, the mechanism underlying the activation of intrinsic foot muscles during force generation and whether there exists a difference between these two postures still remain unclear.

Research Question: Are the activities of intrinsic foot muscles affected by standing and sitting postures during gradual force generation?

Methods: Seventeen men participated in the laboratory based cross-sectional study.

Head Impact in Blind Football During the Tokyo Paralympics: Video-Based Observational Study.

Head impacts during blind football are common and have high injury rates; however, their characteristics and impact are still underreported. We compared head impact characteristics in blind football players with and without falls on all 18 official blind football match videos from the Tokyo 2020 Paralympic games. The rate of head impacts with falls was significantly higher in the preliminary phase, offense phase, and during dribbling.

Association of the intrinsic foot muscles and plantar fascia with repetitive rebound jumping and jump landing in adolescent athletes: An ultrasound-based study.

Background: The characteristics of foot structure in adolescents and adults are different, affecting sports performance and leading to the progression of foot and lower extremity disorders.

Research Question: This study aimed to investigate the relationship between the intrinsic foot muscles (IFM) and plantar fascia morphology and the repetitive rebound jumping and jump landing ability in adolescent athletes.

Methods: A total of 60 adolescent athletes (35 boys and 25 girls) participated in this study.

Investigation of the Relationship Between the Morphology of the Toe Flexor Muscles in Ballet Dancers and the Postural Stability During Standing on Demi-Pointe: A Cross-Sectional Study.

This study investigated how toe flexor muscles are related to postural stability in 11 ballet dancers and 12 non-dancers.
Methods: Toe flexor strength (TFS), cross-sectional areas (CSA) of the abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, flexor hallucis longus (FHL), and flexor digitorum longus, and center of pressure (COP) displacement during single-leg demi-pointe were measured. Correlations between toe flexor strength and COP displacement and between CSA and COP displacement within each group were calculated using Pearson's correlation coefficient or Spearman's correlation coefficient.

Quantitative evaluation of the vertical mobility of the first tarsometatarsal joint during stance phase of gait.

We determined how the in vivo mobility of the first tarsometatarsal (TMT) joint can be quantified during gait. Twenty-five healthy participants (12 females) with no history of foot disorders were included. Non-invasive ultrasound (US) with a three-dimensional motion analysis (MA) system was used to evaluate the kinematic characteristics of first TMT joint during stance phase of gait.

The relationship between the severity of perimenstrual symptoms and a regular exercise habit in Japanese young women: a cross-sectional online survey.

Background: Experiencing perimenstrual symptoms is a major health concern for young women. Women in the reproductive age experience menstruation about once a month, and many experience perimenstrual symptoms. Drug therapies such as painkillers (commonly used) and hormonal medications help to achieve symptomatic relief from perimenstrual symptoms.