Background:Chronic widespread pain (CWP) is a core symptom of fibromyalgia that is associated with significant morbidity and mortality. Despite the widespread recommendation for physical activity (PA) in management, the heterogeneity of PA prescriptions limits the in-depth evaluation of its efficacy. By triangulating clinical interventional evidence with human genetic evidence, the aim of this study was to investigate the role of influencing factors such as PA mode, course of treatment, and intensity on PA in the prevention and treatment of CWP. Methods:Ten international and regional databases were searched for articles published between January 2014 and July 2024. Randomized control trials with CWP or fibromyalgia as an entry criterion and PA as an intervention were included. Meta-analyses were performed using fixed- or random-effects models based on heterogeneity, and subgroup analyses were conducted. Mendelian randomization (MR) was used to estimate the effects of the genetic variants linked to PA intensity on CWP risk. Results:The analysis included 11 studies with 540 participants. PA effectively improved pain perception (MD: -1.47; 95% CI: -2.23, -0.72), depression (MD: -4.77; 95% CI: -7.40, -2.14), and overall quality of life (SMD: -1.43; 95% CI: -2.16, -0.69). MR analysis revealed that several PA intensities were associated with reduced susceptibility to CWP: walking for pleasure (OR: 0.950; 95% CI: 0.934-0.966), light do-it-yourself (DIY) (OR: 0.976; 95% CI: 0.961-0.992), strenuous sports (OR: 0.923; 95% CI: 0.880-0.967), and other exercises (OR: 0.957; 95% CI: 0.942-0.973). Conclusion:PA interventions are beneficial for reducing pain perception and mood disorders and enhancing the quality of life of patients with CWP. A treatment course of approximately three months is preferable, with Ba-Duan-Jin potentially more effective than other PAs, and high-intensity PA offers the most significant protective effect against CWP.

BACKGROUND:Functional constipation (FC) is a common health issue in children, impacting their health-related quality of life. Chinese pediatric therapeutic massage, also called Chinese pediatric Tuina, a traditional Chinese manual manipulation therapy, has been utilized for managing FC in children. This study examined the effects of 2 types of pediatric Tuina therapy, regular and Han's style, on FC in children diagnosed based on the Rome IV criteria and with the type of food stagnation accompanied by interior heat/inflammation in traditional Chinese medicine. METHODS:The study involved 196 children aged 1 to 7 years (mean [M] age 2.7 ± 1.5 years) diagnosed with FC for 3 to 6 months based on Rome IV criteria and traditional Chinese medicine's diagnosis of food stagnation with internal heat/inflammation. Two groups of 98 participants each were randomly formed. One group received regular pediatric Tuina therapy, while the other received Han's style pediatric Tuina therapy for 2 sessions. Each session lasted for 7 days with a one-day break, and a 3-day break was scheduled between the 2 sessions. Bristol stool scale, scale of defecation difficulty, scale of stooling duration, scale of stooling frequency, and abdominal bloating were assessed at pretreatment, post-first session, post-second session, and 1-week after the second session. Paired t-tests and independent t-tests were used to examine significant differences in measures among data collected from different time points within each group and between the 2 groups, respectively. RESULTS:Both types of Tuina therapy (regular and Han's style) demonstrated significant improvements in all measures compared to pre-Tuina (P < .05). Han's style Tuina showed significantly better effects (P ≤ .01) than regular Tuina. CONCLUSION:Chinese pediatric Tuina therapy significantly improved FC symptoms caused by food stagnation with interior heat/inflammation in the studied population, with Han's style having certain advantages. The Chinese Tuina therapy used in the study could be recommended as an alternative management approach for FC in children.

RATIONALE:Coccyx fractures and subluxations are commonly caused by trauma, often leading to severe pain and restricted mobility. Traditional treatments focus on analgesia and immobilization; however, recovery periods are prolonged. This study explores the efficacy of acupuncture combined with Tai Chi in promoting rehabilitation for coccyx fractures. PATIENT CONCERNS:A 34-year-old female patient experienced sacrococcygeal pain and limited mobility after falling on her buttocks while skiing on February 13, 2025. DIAGNOSES:Computed tomography imaging indicated a suspected fracture of the S5 vertebral body, a possible subluxation of the Co1 vertebral body, and soft tissue swelling with effusion in the sacrococcygeal region. INTERVENTIONS:The treatment consisted of lumbosacral acupuncture, targeting the Baliao (Shangliao, Ciliao, Zhongliao, Xialiao) and Ashi points (local tender spots), supplemented by daily Five-Form Tai Chi exercises. Acupuncture sessions were conducted once daily, with needles retained for 10 minutes, over a consecutive period of 14 days. Furthermore, the Tai Chi exercises were performed twice daily, with each session lasting 20 minutes, also spanning a duration of 14 days. OUTCOMES:Post-treatment, the Visual Analog Scale pain score decreased from 7 to 3. Follow-up computed tomography revealed no obvious fractures on sacrococcygeal plain scans, with recommendations for follow-up or magnetic resonance imaging if necessary. The patient showed significant functional improvement and reduced anxiety. LESSONS:Acupuncture combined with Tai Chi effectively alleviates pain, promotes functional recovery, and accelerates fracture healing in patients with coccyx fractures and subluxations.

BackgroundChronic low back pain (CLBP) is a common public health problem. Progressive loss of muscle strength leads to long-term chronic pain and disability. Yijinjing exercises, an ancient therapy dating back thousands of years, are widely used in China to treat low back pain. However, little is known about its benefits and scientific evidence for back extensor strength. This trial aimed to assess the efficacy of Yijinjing on disability and dorsal extensor strength in patients with CLBP. ObjectiveWe present a randomized controlled study to evaluate the efficacy of the traditional Chinese exercise Yijinjing on disability and back extensor strength in patients with CLBP. MethodsThis is a 2-arm, parallel-design, assessor-blinded, and analyst-blinded randomized controlled trial. The 106 participants with CLBP who were recruited will first receive basic traditional Chinese manual therapy to help relieve their physical discomfort. Second, they will be randomly divided into a Yijinjing group (n=53) and a control group with functional exercises (n=53) at a ratio of 1:1. The interventions for both groups will be carried out twice a week for 4 weeks. Patients in both groups will be followed up at 1 and 3 months after the intervention. The primary outcome is disability (measured by the Oswestry Disability Index). The secondary outcomes included pain intensity (assessed by the Numerical Rating Scale), data from isokinetic dynamometry, flexibility (assessed by the fingertip-to-floor test), mood (evaluated by the Pain Catastrophizing Scale and Fear Avoidance Beliefs Questionnaire), and quality of life (measured by the EQ-5D-5L). All adverse effects will be assessed using the Treatment Emerging Symptoms Scale, and data will be analyzed using an intention-to-treat analysis. ResultsThe trial was funded in December 2023. The Institutional Ethics Committee of Yueyang Hospital of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, approved this study. The first patient was enrolled in February 2024, and as of August 2024, a total of 106 participants have been recruited. Data analysis has not yet begun and is expected to be published in January 2025. The protocol has been registered with the Chinese Clinical Trial Registry (ChiCTR2400081105). ConclusionsIf this trial proves effective, it will guide the setup of a randomized controlled trial to demonstrate whether traditional Chinese exercise Yijinjing improves disability in patients with CLBP and is more effective than usual stretching exercises. Trial RegistrationChinese Clinical Trial Registry ChiCTR2400081105; https://www.chictr.org.cn/showprojEN.html?proj=214425 International Registered Report Identifier (IRRID)DERR1-10.2196/67557

Rationale:Urinary calculi are hard mineral deposits that typically require medication or surgery, such as lithotripsy. This case report presents traditional Chinese exercises (TCEs) as a potential alternative for stone expulsion.Patient concerns:A 41-year-old male with no history of urinary tract stones, experienced sudden severe lower back and abdominal pain accompanied by nausea and vomiting.Diagnosis:Computed tomography scan revealed a small calculus at the distal end of the left ureter (within the bladder wall), approximately 2 mm in size, with mild hydronephrosis in the ureter and renal pelvis.Interventions:The patient was initially prescribed medication for pain relief and was advised to engage in TCEs.Outcomes:Follow-up computed tomography scan after the exercise regimen showed complete expulsion and disappearance of the urinary calculi. The patient reported significant improvement in physical and mental health with no recurrence of calculi observed in subsequent checkups.Lessons:This case suggests that TCEs may facilitate the expulsion of small urinary calculi, offering a noninvasive treatment option. Further research is needed to confirm the therapeutic effects of TCEs on urinary calculi and to explore its potential mechanisms.

Objective The traditional Chinese mind–body exercise, Baduanjin, has remained popular for a thousand years for strengthening the body, promoting health and preventing chronic diseases. However, research on its exercise intensity is lacking. This study measured the exercise intensity of beginners practicing Baduanjin to provide scientific evidence for health promotion and exercise prescriptions. Methods A total of 20 healthy adults (13 males, 7 females) aged between 35 and 45 years, who had not practiced Baduanjin previously, were recruited. The average METs, HR, HRR, VO2, VO2/kg, VO2/HR, RR, RQ and VE were measured using the Italian Cosmed/K5 wireless portable exercise cardiopulmonary testing system. Results The average METs during Baduanjin was 2.92 ± 0.65. The mean maximum and mean average HR were 109.35 ± 17.83 and 95.34 ± 13.99, respectively. During Baduanjin, the exercise intensity indicators showed significant increases (P < 0.001) in VO2, VO2/kg, METs, HR, VO2/HR, RR and VE compared with the resting state. Additionally, the mean RQ increased (P < 0.05). Conclusion Baduanjin is a low-intensity exercise for beginners. HR reached its maximum in the later stages of Baduanjin, significantly decreased immediately after exercise and returned to near-resting levels within three minutes post-exercise. Baduanjin, as a low-intensity exercise, could be recommended for population members suitable to practice.

Background Parkinson’s disease (PD) is associated with changes in gait and posture, which increases the rate of falls and injuries in this population. Tai Chi (TC) training enhances the movement capacity of patients with PD. However, the understanding of the effect of TC training on gait and postural stability in PD is lacking. This study aims to examine the effect of biomechanical-based TC training on dynamic postural stability and its relationship with walking performance. Methods/design A single-blind, randomized control trial of 40 individuals with early-stage PD was conducted (Hoehn and Yahr stages 1 to 3). Patients with PD will be randomly assigned to either the TC or control group. The TC group will participate in a biomechanical-based TC training program that is formed based on the movement analysis of TC and will be practiced thrice a week for 12 weeks. The control group will be required to engage in at least 60 min of regular physical activity (PA) on their own for three times per week for 12 weeks. The primary and secondary outcomes will be assessed at baseline and at 6 and 12 weeks after commencing the study protocol. The primary outcome measures will include dynamic postural stability indicated by the center of mass and center of pressure separation distance and clearance distance of the heel and toe measured during fixed-obstacle crossing. The secondary measures are gait speed, cadence, step length during level surface walking (simple task), and fixed-obstacle crossing (challenging task). The Unified Parkinson’s Disease Rating Scale, single leg-stance test with eyes open and closed, and three cognitive scores (Stroop Test, Trail Making Test Part B, and the Wisconsin Card Sorting Test) were also employed. Discussion This protocol could lead to the development of a biomechanics TC training program for the improvement of gait and postural stability among individuals with PD. The program could enhance the understanding of the effect of TC training on gait and postural stability and could help improve or preserve the postural stability, self-confidence, and active participation in social activities of the participants, thus enhancing their overall quality of life. Trial registration ClinicalTrials.gov NCT04644367. Registered on 25 November 2020.

Parkinson's disease (PD) affects gait and postural stability. Tai Chi (TC) is recommended for PD for management of the condition, however biomechanical understanding to its effects on gait and postural stability is limited. This study aimed to examine the effects of an online 12-week biomechanical-based TC intervention on gait and posture in people with PD. Fifteen individuals in early-stage PD were recruited (Hoehn & Yahr stages 1-2). The TC intervention program was 60 ​min session, three times weekly for 12 weeks. The pre- and post-intervention test in obstacle crossing, timed-up-and-go (TUG) test, and single leg standing (SLS) with eyes open (EO) and closed (EC) were conducted. Gait speed, crossing stride length, clearance height of the heel and toe, anterior-posterior (AP) and medial-lateral (ML) displacement and velocity of the center of mass (COM) and separation of the COM-center of pressure (COP) were analyzed. The participants significantly improved their pre-vs. post-TC intervention performance on TUG test (p ​= ​0.002). During obstacle crossing, the participants significantly increased crossing stride length of the trailing foot, increased AP COM displacement and decreased ML COM-COP separation (p ​< ​0.05); the maximal dorsiflexion angle of the leading limb significantly increased and maximal plantarflexion angle of the trailing limb significantly decreased (p ​< ​0.05). A 12-week biomechanical-based online TC training was effective towards improvement of gait and postural stability among people in the early-stage of PD. The TC program and online training could be applied for management of PD.

This study examined the maximum joint angles and moments, and electromyography (EMG) activity of the lower limbs in an experienced Tai Chi (TC) practitioner in performing four dynamic (Repulse Monkey, Wave-hand in Clouds, Brush Knee Twist Step, and Lateral Forward Step) and three static TC movements (Starting Form, Hero Touch Sky, and Push Hand Back) and compared them with the measures from walking. Integrated EMG (iEMG) and peak EMG of the rectus femoris, adductor longus, tibialis anterior, semitendinosus, erector spinae, gluteus medius, tensor fasciae latae, medial and lateral gastrocnemius muscles were analyzed. One-way analysis of variance showed that compared with walking, TC presented 1) significantly larger hip flexion (71.4° vs. 42.2°) and abduction angles (11.9° vs. 5.3°), smaller knee flexion (45.2° vs. 71.1°) and abduction angles (13.0° vs. 27.7°), larger ankle dorsiflexion (41.4° vs. 11.3°) and abduction angles (8.8° vs. 7.2°); 2) hip flexion moment and knee flexion and abduction moment were significantly larger. Ankle dorsiflexion moment were significantly smaller, whereas ankle abduction moment was significantly larger in two TC movements; and 3) the EMG activity of the muscles in TC varied from 10% to 610% of walking. The knee extensors, hip adductors and abductors had significantly higher peak EMG (430% ​± ​40%, 240% ​± ​30%, and 320% ​± ​90%) and iEMG values (610% ​± ​30%, 311% ​± ​30%, and 1.4% ​± ​20%), respectively. The findings suggested that these TC movements could be a good option for the improvement of muscle strength and range of motion of the lower limbs.

OBJECTIVE:The aim of this study was to examine the effect of Liu-zi-jue exercise on the respiratory symptoms, quality of life, and mental health of patients with mild coronavirus disease 2019 (COVID-19).METHODS:A single-center randomized controlled trial was conducted with 104 patients with mild COVID-19. The patients were randomly assigned to the Liu-zi-jue plus conventional therapy group and conventional therapy group. The outcome measures included Modified Borg Dyspnea Scale (MBDS) score, Patient Health Questionnaire-9 (PHQ-9) score, Fatigue Scale-14 (FS-14), respiratory symptoms, and vital signs. Data were collected on the first and sixth days of hospitalization and on the discharge day.RESULTS:Repeated-measures ANOVA revealed that the whole scales all showed a downward trend in the two groups (all 0.05). The results of single-group effect suggested that the whole scale score in the intervention group was significantly lower than that in the control group at the sixth day of hospitalization. Compared with the control group, only the MBDS, expectoration, and FS-14 scores showed significantly lower scores at the discharge day ( 0.001, 0.011, 0.002). Comparison within the group showed that all the variables were significantly different at the three time points with a decreasing trend ( 0.05), except for the PHQ-9 and expectoration scores ( 0.331, 0.052). All patients' vital signs remained within a stable normal range throughout the hospital stay.CONCLUSION:The results suggested that Liu-zi-jue exercise as a complementary and alternative therapy showed beneficial effects on improving the symptoms (shortness of breath, fatigue, and cough), quality of life, and mental health of patients with mild COVID-19.

目的 比较老年男性和年轻男性在行走时足底动力学特征的差异,探讨增龄对足底动力学的影响.方法 应用鞋垫式压力测试系统比较13名老年男性和14名年轻男性在串联行走时左脚的受压时长、受压支撑百分比、开始受压支撑百分比、结束受压支撑百分比、最大压强、最大压强支撑百分比、平均最大压强、时间压强积分、最大压力、最大压力支撑百分比、平均压力和时间压力积分的差异.结果 老年组除内侧足弓外所有分区的受压时长明显大于年轻组,同时外侧足跟、外侧足弓开始受压支撑百分比明显大于年轻组,而内侧足跟、第2、3跖骨受压结束百分比明显小于年轻组;老年人整个足底最大压力和平均压力以及第2、3跖骨平均最大压强和最大压力明显小于年轻组.老年人整个足底、第4、5跖骨和4个小脚趾的时间压强积分以及整个足底、足跟和4个小脚趾的时间压力积分明显大于年轻组.结论 前后脚串联行走时,足底筋膜机能减退可能是老年人姿势控制能力下降的主要原因之一,趾长屈肌和趾短屈肌的屈趾作用增强对老年人姿势稳定性提高有一定的代偿作用.

目的:探讨不同足落地模式跑者在不同路面跑步时足底压力的特征.方法:研究纳入41名习惯后足落地跑者(rearfoot strike,RFS)、37名习惯非后足落地跑者(non-rearfoot strike,NRFS),使用足底压力系统测量不同足落地模式跑者在4种不同硬度地面[混凝土、橡胶、人造草地、乙烯-醋酸乙烯酯共聚物缓冲垫(EVA)泡沫板]跑步时足底峰值压力(MF)、压力时间积分(FTI)、峰值压强(PP)、压强时间积分(PTI)和接触面积(CA)的差异.结果:仅PP在足跟,PTI在前足外侧区域落地模式和跑步地面有显著的交互作用.与NRFS跑者相比,RFS跑者全足CA(P<0.001)、全足MF(P=0.005)、全足FTI(P<0.001)显著较大,后足和中足区域所有指标均显著较大(P<0.001),前足区域PTI和FTI显著较小,前足内侧PP和MF显著较小.相较于其他3种硬度路面,EVA有更高的全足CA(P=0.016)、更低的全足PP(P<0.001),在前足中部和外侧MF、PTI、FTI均显著较小(P<0.001),中足内侧和前足内侧CA显著较大(P<0.001).结论:后足落地跑者在不同硬度地面跑步时足底压力均显著较大,且集中在足跟的压力可能传递到膝关节使其承受较大负荷.尽管非后足落地跑者足底压力较小,但其足底压力主要集中在前足内侧区域.EVA泡沫板路面虽在前足有较低的峰值压力,但由于其硬度较小,跑步时内侧纵弓高度会显著降低.因此,跑者应根据自身情况合理选择跑步路面和足落地模式,以避免运动损伤的发生.

This study was aimed at exploring the biomechanical characteristics of the lower extremity amongst three typical yoga manoeuvres. A total of thirteen experienced female yoga practitioners were recruited in the current study; they were all certified with the Yoga Alliance. A three-dimensional motion capture system with 10 cameras combined with four synchronised force plates was used to collect kinematics of the lower extremity and ground reactive force whilst the participants performed the crescent lunge pose, warrior II pose, and triangle pose. One-way repeated ANOVA was used in exploring the differences amongst the three yoga movements, and the significance was set to alpha < 0.05. The triangle pose performed the largest range of motion (ROM) of the hip (90.5° ± 22.9°), knee (68.8° ± 23.1°), and ankle (46.4° ± 11.3°) in the sagittal plane and the hip (54.8° ± 6.5°), knee (42.4° ± 12.8°), and ankle (4.8° ± 1.7°) in the frontal plane amongst the three manoeuvres (P < 0.05). No significant difference was found for the hip and ankle joint moment amongst the three manoeuvres (P > 0.05). Knee joint travelled into 9.5° of extension and slight adduction of 1.94° whilst expressing the largest knee joint adduction moments (0.30 ± 0.22 Nm/kg) in the triangle pose. The distribution of the angular impulse of the lower limb joints indicated that the hip joint contributed significantly the most in the sagittal and frontal planes of the three yoga manoeuvres (P < 0.05), ranging from 51.67% to 70.56%. Results indicated that triangle pose may be superior to the other two manoeuvres, which improved hip joint ROM, strength, and dynamic stability. However, knee injuries such as osteoarthritis (OA) should be considered because of the large knee extensor angle and adductor moments.

The effects of body mass and sex on lower limb biomechanics during ascent and descent were examined in participants aged 50 to 75 with normal weight (n ​= ​19), overweight (n ​= ​18), and obese (n ​= ​8). Peak joint angles and joint moment of the lower limb were analyzed with the VICON motion analysis system. Results from multivariate analysis of variance showed that during descent, the overweight participants had significantly higher knee extensor moment (0.98 ​± ​0.30 ​N∙m/kg-1) than the normal-weight participants (0.70 ​± ​0.29 ​N∙m/kg-1). The obese group had significantly higher ankle abductor moment (0.21 ​± ​0.11 ​N∙m/kg-1) than the normal weight (0.12 ​± ​0.08 ​N∙m/kg-1) and overweight groups (0.09 ​± ​0.06 ​N∙m/kg-1). During ascent, the obese participants had significant higher hip flexor moment (0.42 ​± ​0.20 ​N∙m/kg-1) than overweight participants (0.22 ​± ​0.17 ​N∙m/kg-1). Significant sex differences were found in knee extension angles (4.2 ​± ​3.4° vs 7.0 ​± ​3.3°) during descent, plantar flexion angles during ascent (23.7 ​± ​5.3° vs 15.6 ​± ​3.7°) and descent (29.9 ​± ​5.0° vs 22.1 ​± ​7.9°), and ankle adduction angles (6.8 ​± ​4.8° vs 2.5 ​± ​2.5°) during ascent. It is concluded that body mass has significant impact on joint loading of lower limbs during stair walking. Being overweight and obese increased hip joint loading during ascent, and knee and ankle joint loading during descent in older adults. Sex difference in joint kinematics was presented during stair walking regardless of the body mass.

高跟鞋是女性日常生活中最常穿着的鞋款之一,研究发现穿着高跟鞋会改变人体正常的姿势,是引起下肢骨骼肌肉系统损伤的因素之一.本文对目前高跟鞋对人体姿势稳定性影响的研究进行综述,意在探讨穿高跟鞋所致损伤与其发生的生物力学机制,以期为鞋类的设计提供科学建议,从人体科学的角度为女性预防高跟鞋相关损伤提出合理建议.

We examined the effects of long-term exercise on age-related decline in static balance control through centre-of-pressure (CoP) measurements of four groups of participants: older controls, younger controls, older Tai Chi exercisers and older joggers. The participants stood quietly in a tandem stance on a force platform for 30 s with eyes open (EO) and eyes closed (EC). The older controls showed remarkably larger CoP and EC/EO ratios than younger controls and older Tai Chi exercisers. The EC/EO ratios of velocity in the mediolateral direction of older joggers were significantly smaller than those of older controls. Results suggest that the static balance of older controls showed a significant decline caused by age-related changes. Long-term Tai Chi and jogging, particularly the former, contributed to static balance control in older people. Older adults relied more on visual information in static postural control than young people. Tai Chi would be an ideal exercise for improving static balance in older people.

Background Wearing high-heeled shoes and carrying asymmetrical loads are common in ladies. However, knowledge of the effects of wearing high-heeled shoes on balance and lower-extremity biomechanics in experienced and novice high-heeled shoe wearers is lacking. The study aims to examine the effects of high-heeled shoes and asymmetrical load carrying on joint kinematics and kinetics of the lower extremity during walking as well as balance in experienced and novice high-heeled shoe wearers. Methods Fifteen experienced and 15 novice high-heeled shoes wearers participated in this study. Using a motion analysis system, kinematic and kinetic data were collected while participants walked at their preferred speed in six conditions created from two types of shoes (9-cm high-heeled shoes and flat-heeled shoes) and three weights of symmetrical load (0%, 5%, and 10% of body weight). Stride time and length, step length, double support time, peak joint angles, and joint moments in a sagittal plane were analyzed. Single-leg and tandem-leg stance tests were performed in each condition. Results Compared with experienced high-heeled shoe wearers, novice high-heeled shoe wearers had longer double support time and shorter stride length during 10% of body weight asymmetrical load walking; walked with greater knee flexion angle, smaller knee range of motion, and smaller ankle dorsiflexor moment; and scored lower in the single-leg and tandem-leg stance tests. Conclusions Novice high-heeled shoe wearers need to alter their lower-limb joint angles and moments to adjust to high-heeled shoes to achieve balance during gait while carrying an asymmetrical load.

Twenty-four healthy adults, including 12 females and 12 males, participated in the study. Each female participant completed three trials in three different phases of one menstrual cycle, which included follicular, ovulatory, and luteal phases. The study aimed to investigate whether there is any difference in joint kinetic sense, neuromuscular coordination, and isokinetic muscle strength (a) between healthy males and females at different phases of the menstrual cycle and (b) between females at different phases of the menstrual cycle. The outcome measures included the number of jumps in the square-hop test and ankle and knee proprioception, which were assessed by an electric-driven movable frame rotated at 0.4 deg/s and isokinetic muscle strength measured by a computerized dynamometer (Biodex). For the square-hop test (p = .006), ankle dorsiflexion/plantar flexion (p < .05), knee flexion/extension (p < .05), the relative peak torque of the isokinetic muscle strength at the 60° and 180° knee flexion/extension (p < .001), and the 30° and 120° ankle plantar flexion/dorsiflexion (p < .05) between females and males showed significant differences. For the females at different phases of the menstrual cycle, significant differences were found on ankle dorsiflexion (p = .003), plantar flexion (p = .023), knee extension (p = .029), the square-hop test (p = .036), and relative peak torque of isokinetic muscle strength at 180° knee flexion (p = .029). This study demonstrated that there are sex differences in lower limb proprioception and mechanical function. Females at ovulatory and luteal phases have better lower limb proprioception than at the follicular phase.

Background. High heel shoes (HHS) can affect human postural control because elevated heel height (HH) may result in plantar flexed foot and limit ankle joint range of motion during walking. Effects of HH and HHS wearing experience on postural stability during self-initiated and externally triggered perturbations are less examined in the literature. Hence, the objective of the present study is to investigate the influences of HH on human postural stability during dynamic perturbations, perceived stability, and functional mobility between inexperienced and experienced HHS wearers. Methods. A total of 41 female participants were recruited (21 inexperienced HHS wearers and 20 experienced HHS wearers). Sensory organization test (SOT), motor control test (MCT), and limits of stability (LOS) were conducted to measure participant's postural stability by using computerized dynamic posturography. Functional reach test and timed up and go test were performed to measure functional mobility. The participants' self-perceived stability was assessed by visual analog scale. Four pairs of shoes with different HH (i.e., 0.8, 3.9, 7.0, and 10.1 cm) were applied to participants randomly. Repeated measures analysis of variance was conducted to detect the effects of HH and HHS wearing experience on each variable. Results. During self-initiated perturbations, equilibrium score remarkably decreased when wearing 10.1 cm compared with flat shoes and 3.9 cm HHS. The contribution of vision to postural stability was larger in 10.1 cm HHS than in flat shoes. The use of ankle strategy worsened when HH increased to 7 cm. Similarly, the directional control of the center of gravity (COG) decreased for 7 cm HHS in LOS. Experienced wearers showed significantly higher percentage of ankle strategy and COG directional control than novices. Under externally triggered perturbations, postural stability was substantially decreased when HH reached 3.9 cm in MCT. No significant difference was found in experienced wearers compared with novices in MCT. Experienced wearers exhibited considerably better functional mobility and perceived stability with increased HH. Conclusions. The use of HHS may worsen dynamic postural control and functional mobility when HH increases to 3.9 cm. Although experienced HHS wearers exhibit higher proportion of ankle strategy and COG directional control, the experience may not influence overall human postural control. Sensory organization ability, ankle strategy and COG directional control might provide useful information in developing a safety system and prevent HHS wearers from falling.