A quantitative assessment of the anterior tibiofibular gap with and without weight-bearing in healthy adults: An ultrasound-based study.

BACKGROUND: Difficulties in the accurate evaluation of tibiofibular clear space in plain radiographs are diagnostic problems in the clinical setting of syndesmosis injury. This study aimed to quantify the anterior tibiofibular gap (ATFG) with weight-bearing using ultrasonography. METHODS: In total, 32 healthy adults (16 men and 16 women) with 64 feet participated in this cross-sectional study. The ATFG was measured along the anterior inferior tibiofibular ligament for a US assessment conducted in both sitting and standing postures. The ankle joint was set on the tilt table at four different angles as follows: plantar flexion, 20° (P20); neutral position (N); dorsiflexion, 20° (D20); and dorsiflexion, 20°+ external rotation, 30° (D20ER30). The ankle joint position, sex, and side-to-side values were compared with and without weight-bearing. RESULTS: Under all ankle angle conditions, the ATFG was wider in the standing posture than in the sitting posture (p < 0.001). In both sitting and standing postures, the ATFG widened with increasing dorsiflexion angle, eventually reaching a maximum at D20ER30. The widening ratio (D20ER30/N) in the standing posture was higher in women than in men (p < 0.05). No statistical differences were identified side-to-side differences in the ATFG. CONCLUSIONS: Ultrasound measurements for identifying unphysiological increases in ATFG with weight bearing, especially given the side-to-side differences, may provide a means for quantitatively assessing syndesmosis injury in a clinical setting. Further research is warranted to clarify direct attribution as a clinical diagnostic utility of the ATFG measurements for syndesmosis injuries.

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: 18.2 ± 1.8 kg/m2) were included and performed demi-plié in control, functional turnout, and forced turnout conditions. Ultrasound imaging synchronized with a three-dimensional motion analysis system was used for measuring the vertical locations of the first metatarsal and medial cuneiform (MC) to evaluate the first TMT joint mobility. Plantar displacement of MC and the first TMT joint mobility in the forced turnout were the greatest among the 3 conditions. Multiple regression analysis indicated that the greater extent of the forcing angle might increase the displacement of MC and the first TMT joint mobility. Evaluating the sagittal mobility of the first TMT joint in the forced turnout can assist in understanding the association between inappropriate techniques including the forced turnout and HV development in ballet dancers. Since the excessive mobility of the first TMT joint is a factor in HV development, the acquirement of adequate active turnout may have the potential to prevent HV development in ballet dancers.

Effect of ball positions on trunk, hip, knee, and ankle joint kinematics and kinetics during a spike jump in volleyball.

BACKGROUND: Anterior cruciate ligament injuries are serious conditions encountered in volleyball players and occur frequently during spike jump landings. During spike jumps, the lower limb kinematics and kinetics during landing may be altered in relation to the ball position. RESEARCH QUESTION: Does the ball position have an effect on lower-limb kinematics and kinetics during spike jumps? METHODS: We measured the lower limb kinematics and kinetics of 20 healthy female college volleyball athletes during a spike jump using a three-dimensional motion analysis system. The ball positions were set to normal, dominant, and non-dominant positions. A repeated analysis of variance was used to compare the lower limb kinematics and kinetics at the initial contact and the maximum knee flexion during jump landing. Additionally, statistical parametric mapping analysis was used to analyze changes over time during the spike jumps. RESULTS: At the initial contact of the spike jump landing, the knee valgus angle, trunk lateral bending angle, and maximum knee valgus moment when the ball was set at the non-dominant position increased compared to those at the dominant position. Statistical parametric mapping analysis showed no significant change in knee valgus angle and moment of jump landing. CONCLUSION: Knee valgus angle, trunk lateral bending angle, and maximum knee valgus moment increased with the non-dominant position; furthermore, the risk of ACL injury may also be increased. SIGNIFICANCE: The posture at ball impact may influence the landing kinematics and kinetics. Therefore, it is necessary to pay close attention to movements during and prior to landing.

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. PARTICIPANTS: In total, 36 blind football (men's football 5-a-side) game videos were obtained from the official International Paralympic Committee. PRIMARY AND SECONDARY OUTCOME MEASURES: Head impact was defined as the sudden contact of any object with the head. Videos were analysed to assess the number of scores and head impacts along with their corresponding details (ie, round, playing phase, scoring situation, impact situation, occurrence area, impact object, head impact site, fall and foul). RESULTS: The total number of goals scored at the Tokyo 2020 Paralympic Games was nearly double that at the Rio 2016 Paralympic Games. Regarding head impacts, a total of 2036 cases (Rio 2016, n=1105; Tokyo 2020, n=931) were evaluated. Significant differences were observed in head impact characteristics between the Rio 2016 and Tokyo 2020 Paralympic Games among seven outcomes (round, scoring situation, impact situation, occurrence area, impact object, site of head impact and fall). CONCLUSIONS: Compared with the Rio 2016 Paralympic Games, the Tokyo 2020 Paralympic Games showed an increase in the number of points scored and different head impact characteristics.

First tarsometatarsal joint mobility in hallux valgus during gait: A synchronized ultrasound and three-dimensional motion capture analysis.

PURPOSE: To quantify the vertical translation between the first metatarsal and medial cuneiform during the stance phase of gait in young individuals with and without hallux valgus. DESIGN: This cross-sectional observational study included 34 young adults (male, n = 4; female, n = 30) who were divided into three groups according to the hallux valgus angle: control (< 20°, n = 13), mild hallux valgus (≥ 20° to < 30°, n = 12), and moderate hallux valgus (≥ 30°, n = 9). The mobility of the first tarsometatarsal joint was evaluated during the stance phase using B-mode ultrasound synchronized with a motion analysis system. RESULTS: The medial cuneiform shifted more plantar during the early phase in mild hallux valgus and during the middle and terminal phases in moderate hallux valgus than in control. The severity of the hallux valgus was correlated with a trend toward plantar shift of the medial cuneiform. The first metatarsal was located more dorsal than the medial cuneiform; however, there was no significant variation. No significant differences in the peak ankle plantarflexion angle and moment were noted between the groups. CONCLUSION: The hypermobility of the first tarsometatarsal joint, especially plantar displacement of the medial cuneiform in the sagittal plane, was found in young individuals with hallux valgus during the stance phase of gait, and the mobility increased with the severity of hallux valgus. Our findings suggest the significance of preventing hallux valgus deformity early in life.