Predicting vertical ground reaction force in rearfoot running: A wavelet neural network model and factor loading.

This study proposed a simple method for selecting input variables by factor loading and inputting these variables into a wavelet neural network (WNN) model to predict vertical ground reaction force (vGRF). The kinematic data and vGRF of 9 rearfoot strikers at 12, 14, and 16 km/h were collected using a motion capture system and an instrumented treadmill. The input variables were screened by factor loading and utilized to predict vGRF with the WNN. Nine kinematic variables were selected, corresponding to nine principal components, mainly focusing on the knee and ankle joints. The prediction results of vGRF were effective and accurate at different speeds, namely, the coefficient of multiple correlation (CMC) > 0.98 (0.984-0.988), the normalized root means square error (NRMSE) < 15% (9.34-11.51%). The NRMSEs of impact force (8.18-10.01%), active force (4.92-7.42%), and peak time (7.16-12.52%) were less than 15%. There was a small number (peak, 4.12-6.18%; time, 4.71-6.76%) exceeding the 95% confidence interval (CI) using the Bland-Altman method. The knee joint was the optimal location for estimating vGRF, followed by the ankle. There were high accuracy and agreement for predicting vGRF with the peak and peak time at 12, 14, and 16 km/h. Therefore, factor loading could be a valid method to screen kinematic variables in artificial neural networks.

Increased cortical activation and enhanced functional connectivity in the prefrontal cortex ensure dynamic postural balance during dual-task obstacle negotiation in the older adults: A fNIRS study.

OBJECTIVE: By analyzing the cortical activation and functional connectivity of the prefrontal cortex (PFC) during dual-task obstacle negotiation in the older adults, cognitive resources allocation and neural regulatory mechanisms of aging brain were shed light on in complex walking conditions. METHODS: Twenty-eight healthy right-handed subjects participated in the study, including 15 men and 13 women (age: 68.6 ± 4.1 years, height: 162.96 ± 6.05 cm, weight: 63.63 ± 9.64 kg). There were four tasks: Normal Walk (NW), Obstacle Negotiation during Normal Walk (NW + ON), Walk while performing Cognitive Task (WCT), and Obstacle Negotiation during Walk while performing Cognitive Task (WCT + ON). Participants wore functional near-infrared spectroscopy (fNIRS) to collect hemodynamic signals from various regions of interest (ROIs) in the PFC, while the three-dimensional motion capture system was used to test the gait velocity. Cognitive task data was recorded. RESULTS: In WCT + ON, the HbO2 concentration change value (△HbO2) of the left dorsolateral prefrontal cortex was significantly greater than that in the other three tasks (p < 0.05), and the△HbO2 of the right dorsolateral prefrontal cortex was significantly greater than that in NW + ON (p < 0.05). The gait velocities in the four tasks were significantly different (p < 0.05) (NW > WCT > NW + ON > WCT + ON). There was no significant difference in cognitive performance between in the WCT and WCT + ON (p > 0.05). In WCT + ON, the left and right dorsolateral prefrontal areas had strong functional connectivity and the left frontal pole was most widely connected to the other ROIs. Compared to that in NW, the functional connectivity of the left prefrontal lobe was significantly enhanced in WCT + ON (p < 0.05). CONCLUSIONS: As walking difficulty increased, the PFC activation in the older adults changed from right-sided to bilateral activation, indicating that the left PFC cognitive resources compensated for the right PFC in dual-task obstacle negotiation. The cognitive resources recruitment in dual-task obstacle negotiation might be achieved by synchronization and coordination of associated brain areas in the PFC, primarily to maintain dynamic postural balance when walking.

The relationships of postural stability with muscle strength and proprioception are different among older adults over and under 75 years of age.

Purpose: The relationships of postural stability with its three potential contributing factors, namely, muscle strength, tactile sensation, and proprioception, have not been clarified at different ages among older adults. Differences in the relationships may explain the increased incidence of falls among older adults 75 and older. This study compared the postural stability and its three factors between the older adults younger or older than 75 and investigated their age-specific relationships. Methods: A total of 152 participants were recruited and divided into younger-old (65-74 years, n = 83) or older-old adults (≥75 years, n = 69) groups. Their Berg Balance Scale (BBS) and the Timed Up and Go (TUG) performance, muscle strength, tactile sensation, and proprioception were tested. The group differences and age-specific relationships of the performance with the three factors were examined. Results: Compared to the younger-older adults, the older-old adults had lower BBS and higher TUG scores, weaker muscle strength, and worse proprioception. Muscle strength and proprioception were correlated with BBS and TUG among the younger-older adults. Only muscle strength but not proprioception among the older-old adults was correlated with BBS and TUG. Conclusion: The older-old adults over 75 years have poorer postural stability, muscle strength, and proprioception compared to the younger-old adults aged 65-74 years. Proprioception provides information on postural stability among younger-old adults but not among older-old adults. Keeping proprioception from deteriorating with age could be a key to reducing falls in older-old adults.

The effect of Tai Chi practice on brain white matter structure: a diffusion tensor magnetic resonance imaging study.

Diffusion tensor imaging (DTI) measures the displacement of water molecules across tissue components and thus provides information on the microstructure of brain white matter. This study examined the effect of Tai Chi and the relation of Tai Chi experiences and skills with brain white matter. Fractional anisotropy (FA) was obtained from the DTI magnetic resonance images of two group participants, namely, the long-term Tai Chi practitioners and sedentary counterparts. Whole-brain voxel-based analysis showed that the Tai Chi group had higher FA in the splenium of corpus callosum (p = 0.015) than the control group. Rank correlation analysis revealed that in the Tai Chi group, the FA value of the splenium of corpus callosum was moderately related with exercise duration (r = 0.45, p = 0.045) but highly related with skill level (r = 0.699, p = 0.001). Long-term Tai Chi practice could benefit to the brain white matter, and these impacts were correlated with exercise duration and skill level.

Performance of older adults under dual task during stair descent.

BACKGROUND: Stair walking, especially in dual-task conditions, is a challenging daily routine for older adults. The purpose of this study is to investigate gait and postural control and explore the possible reasons for the fall risk encountered by healthy older adults under dual-task conditions during stair descent. METHODS: Thirty healthy older female adults (aged 67 ±â€¯1 years, standing height of 1.64 ±â€¯0.17 m, body mass of 66.01 ±â€¯4.27 kg, and education of 8.92 ±â€¯0.95 years) were randomly recruited from local communities and instructed to perform stair descent in a step-by-step manner on a standardized staircase under single-task (stair descent) and dual-task (stair descent with subtraction in series of three) conditions. Multivariate analysis of variance with repeated measures was performed to test the significance of multiple comparisons of kinematic variables in the single- and dual-task conditions. A paired t-test with Bonferroni adjustment was performed when a significant difference was detected. RESULTS: Gait speed, foot clearance, and hip flexion angle at the cross of the support leg decreased considerably, and step width increased remarkably among the healthy older adults under the dual-task condition relative to the situation in the single-task condition during stair descent. CONCLUSION: The gait performance and posture control of the healthy older female adults were disturbed by the second cognitive task. These adults implemented a compensation strategy to enhance their body stability under the dual-task condition during stair descent.

Detraining effects of regular Tai Chi exercise on postural control ability in older women: A randomized controlled trial.

BACKGROUND/OBJECTIVE: This study aimed to investigate the training and detraining effects of Tai Chi (TC) on postural control ability in single leg stance (SLS) by conducting a single-blind randomized controlled trial. METHOD: Forty-eight older women were randomly divided into the TC, brisk walking (BW), and control(C) groups by using computer-generated program. The participants completed a 16-week intervention training and 8-week detraining program. Postural control ability in SLS was tested at the baseline, 16 t h, 20 t h, and 24 t h weeks. The primary outcomes included single-leg stance time (Time) and secondary outcomes included maximal displacement of the center of pressure (COP) in the anterior-posterior (AP) direction (D-ap), maximal displacement of the COP in the medial-lateral (ML) direction (D-ml), total length of the COP trajectories (Lng), and 95% confidence ellipse area of the COP movements (area), mean AP total excursion velocities (V-ap), and mean ML total excursion velocities (V-ml). RESULTS: Significant within-group difference compared with the baseline and between-groups difference compared with control group were found at 16 t h, 20 t h, and 24 t h weeks in the TC group and at the 16 t h and 20 t h weeks in the BW group in all the primary and secondary outcomes. Most of secondary outcomes including Lng, D-ml, V-ml, Area increased significantly at the 24 t h week compared with that at the 16 t h week in BW group. CONCLUSIONS: TC was effective in improving postural control ability and maintaining intervention gains, and was recommended as an appropriate exercise to prevent falls in the older adults.

Effects of Tai Chi Exercise on body stability among the elderly during stair descent under different levels of illumination.

The elderly are prone to stair descent falls under low illumination. Tai Chi, a traditional Chinese conditioning exercise, has been proved to improve body stability by altering body condition, gait, and proprioception. This study investigates whether Tai Chi exercise could improve body stability during stair descent under high and low illumination. Three groups of elderly women who practice Tai Chi, brisk walking, and no exercise were included. They descended from a simulated staircase. Tai Chi participants decreased horizontal velocity, centre of mass (COM) sway, and increased foot clearance compared with other participants, these movements could increase body stability; Compared with under high illumination, Tai Chi participants decreased horizontal velocity, loading rate, braking impulse, and increased inclination angle, COM sway, centre of pressure displacement under low illumination. Tai Chi participants were more sensitive to the difference in illumination, and took corresponding strategies to stabilize their bodies during stair descent.

Effect of 1-year regular Tai Chi on neuromuscular reaction in elderly women: a randomized controlled study.

This study assessed the effect of 1-year regular Tai Chi (TC) on neuromuscular reaction in elderly women. A total of 41 elderly women (55 years-68 years) completed the study. The TC group (n = 21) performed the 24-form TC, while the control group (C, n = 20) was instructed to read newspapers or watch television when the TC group practised. Electromyogram measurements were conducted before and after intervention. After a year-long intervention, the post-test results of between-group neuromuscular reaction time showed significant differences in the rectus femoris (t = 3.607, p = 0.001), semitendinosus (t = 2.678, p = 0.011), anterior tibialis (t = 3.455, p = 0.001), and gastrocnemius muscles (t = 4.061, p = 0.000). Within-group results showed that the TC group had significantly shorter neuromuscular reaction time compared to its baseline value in the rectus femoris (t = 3.066, p = 0.006), semitendinosus (t = 2.485, p = 0.022), anterior tibialis (t = 2.311, p = 0.032), and gastrocnemius muscles (t = 2.462, p = 0.023). Results suggested that year-long regular TC can improve neuromuscular reaction function in elderly women.

Test-retest reliability of a new device for assessing ankle joint threshold to detect passive movement in healthy adults.

This study aimed to evaluate the test-retest reliability of a new device for assessing ankle joint kinesthesia. This device could measure the passive motion threshold of four ankle joint movements, namely plantarflexion, dorsiflexion, inversion and eversion. A total of 21 healthy adults, including 13 males and 8 females, participated in the study. Each participant completed two sessions on two separate days with 1-week interval. The sessions were administered by the same experimenter in the same laboratory. At least 12 trials (three successful trials in each of the four directions) were performed in each session. The mean values in each direction were calculated and analysed. The ICC values of test-retest reliability ranged from 0.737 (dorsiflexion) to 0.935 (eversion), whereas the SEM values ranged from 0.21° (plantarflexion) to 0.52° (inversion). The Bland-Altman plots showed that the reliability of plantarflexion-dorsiflexion was better than that of inversion-eversion. The results evaluated the reliability of the new device as fair to excellent. The new device for assessing kinesthesia could be used to examine the ankle joint kinesthesia.

Effects of exercise on ankle proprioception in adult women during 16 weeks of training and eight weeks of detraining.

This study evaluates the effects of training and detraining on ankle proprioception in terms of kinesthesia in adult women. Sixty participants were randomly assigned to three groups. Tai Chi and Brisk Walking Groups went through a 16-week training period followed by an eight-week detraining period. The ankle plantar-flexion, dorsal-flexion, inversion, and eversion kinesthesia were measured every four weeks. The ankle kinesthesia in plantar/dorsal flexion of both exercise groups decreased, but the Tai Chi Group decreased more and sooner than the Brisk Walking Group. The training effects of Tai Chi exercise were retained but diminished during the detraining. The training effects of Brisk Walking exercise were not retained. The kinesthesia of ankle inversion and eversion remained unchanged after training. The results suggest that Tai Chi exercise is more effective in training ankle proprioception in plantar and dorsal flexion and in retaining the training effects compared with Brisk Walking exercise.

Could Insoles Offload Pressure? An Evaluation of the Effects of Arch-supported Functional Insoles on Plantar Pressure Distribution during Race Walking.

This study investigated the effectiveness of functional insoles on plantar pressure distribution during race walking so as to reduce the high plantar pressure and force on race walkers, who tend to suffer from overuse injury. A total of 20 male race walkers aged 21.19 ± 3.66 years and with a mean height of 178.85 ± 14.07 cm were recruited as participants. Each participant completed a race walking with functional or normal insoles. Plantar pressure insoles were used to collect vertical plantar pressure data. A two-way analysis of variance with a mixed design was used to determine the difference between the two conditions. Results showed that the use of functional insoles reduces the peak pressure and the impulse in the metatarsophalangeal joints and heels and thus suggest that functional insoles reduce the overuse injury risks of these parts. The first ground reaction force peak also decreased. This result suggested that functional insoles reduce the risks of foot and leg injuries.

Effects of backpack weight on posture, gait patterns and ground reaction forces of male children with obesity during stair descent.

This study investigates the effects of backpack weight on posture, gait pattern, and ground reaction forces for children with obesity in an attempt to define a safe backpack weight limit for them. A total of 16 obese (11.19 ± 0.66 years of age) and 21 normal body weight (11.13 ± 0.69 years of age) schoolboys were recruited. Two force plates and two video cameras were used. Multivariate analysis of variance with repeated measures was employed. Obese children showed increased trunk and head forward inclination angle, gait cycle duration and stance phase, decreased swing phase, and increased ground reaction force in the medial-lateral and anterior-posterior directions when compared with male children with a normal body weight. The changes were observed even with an empty backpack in comparison with normal body weight children and a 15% increase in backpack weight led to further instability and damage on their already strained bodies.

Research trends and hotspot evolution of exercise-regulated myokines: a bibliometric analysis from 2003 to 2023.

Background: The lack of physical activity is a common issue in modern society and is considered a major risk factor for various chronic non-communicable diseases. Bioactive factors secreted by skeletal muscle during exercise play a crucial role in inter-organ interactions. Since the concept of "myokines" was proposed in 2004, hundreds of regulatory myokines have been identified. Visual analysis of research on exercise-regulated myokines is significant to explore research hotspots and frontiers in this field. Methods: Research literature on exercise-regulated myokines from 2003 to 2023 in the "Web of Science" database was used as the data source. Knowledge maps were drawn using "VOS Viewer, CiteSpace, and R-bibliometrix" software. Results: A total of 1,405 papers were included, showing a fluctuating yet slow growth in annual publications. The United States and China led in the number of publications and collaboration networks. Harvard University ranked first with 120 publications. CIBER (centrality 0.16) and the University of California System (centrality 0.16) were pivotal in advancing this field. PEDERSEN BK led author rankings with 41 publications and 1,952 citations. FRONTIERS IN PHYSIOLOGY ranked first among journals with 64 publications and the highest g-index (39), while PLoS One had the highest h-index (25) and most citations (2,599). Key co-cited reference clusters included #1 skeletal muscle dysfunction, #2 obesity, #6 ASCs, and #7 adaptive immunocytes. Pontus Boström's paper had a notable citation burst intensity of 77.37. High-frequency keywords were "exercise" (509), "skeletal muscle" (452), and "expression" (293), with long-term keywords such as #0 irisin, #2 insulin resistance, #3 transcription, and #6 physical activity. Recently, keywords like "physical exercise," "resistance exercise," "aerobic exercise," "insulin," and "oxidative stress" have emerged. Conclusion: Research in the field of exercise-regulated myokines shows an overall upward trend. The focus areas include myokines mediated by different types of exercise, the interaction of irisin-mediated muscle with other organs, and the important role of myokine-mediated oxidative stress in exercise simulation.

The effect of multi-component exercise on cognition function in patients with diabetes: A systematic review and meta-analysis.

BACKGROUND: This meta-analysis investigated the influence of exercise on cognitive function in people living with diabetes. METHODS: Stringent criteria for literature inclusion and exclusion were defined. Searches were conducted across four English databases to gather randomized controlled trials investigating exercise interventions for cognitive function in people living with diabetes. Outcome indicators from 1193 subjects across 12 articles were analyzed using RevMan 5.4 software. RESULTS: Exercise intervention demonstrated the ability to mitigate cognitive decline in people living with diabetes, with a combined effect size (standardized mean difference) of 0.91, 95% CI: 0.28, 1.54, P < 0.00001. The intervention effect showed significant modulation by intervention content (I2 = 95%), intervention duration (I2 = 95%), intervention frequency (I2 = 95%), and intervention cycle (I2 = 96%). Among these factors, multi-component exercise, sessions >40 minutes, exercise frequency >4 times per week, and sustained exercise for >6 months were paramount, all with P < 0.05. CONCLUSION: Exercise intervention emerges as a viable strategy for delaying cognitive decline in people living with diabetes. Its efficacy is subject to modulation by various variables. Optimal intervention includes multi-component exercise, individual sessions lasting 40-60 minutes, exercising >4 times a week, and continuous exercise for over 6 months.

Balance Control is Sequentially Correlated with Proprioception, Joint Range of Motion, Strength, Pain, and Plantar Tactile Sensation Among Older Adults with Knee Osteoarthritis.

BACKGROUND: Patients with knee osteoarthritis (KOA) are at high risk for falls, which is attributed to their impaired balance control. Identifying factors associated with balance control facilitates the development of precise KOA rehabilitation programs. This study was to investigate the correlations of balance control with proprioception, plantar tactile sensation (PTS), pain, joint range of motion (ROM), and strength among older adults with and without KOA, as well as the magnitudes and sequence of correlation of these factors to balance control. METHODS: A total of 240 older adults with (n = 124, female: 84, age: 68.8 ± 4.0 years) and without (n = 116, female: 64, age: 67.9 ± 3.5 years) KOA were recruited and assigned to the KOA and control groups. Their proprioception, PTS, pain, ROM, and strength were measured. Pearson or Spearman correlations were used to test whether they were significantly related to their Berg Balance Scale (BBS), and factor analysis and multivariate linear regression were used to determine the degrees of correlation between each factor and the BBS. RESULTS: Compared to the control group, the KOA group had lower BBS score, larger proprioception and PTS thresholds, smaller ROM, and less strength (p: 0.008, < 0.001-0.016, < 0.001-0.005, < 0.001-0.014, and < 0.001-0.002, respectively). In the KOA group, the BBS was weakly to moderately correlated with proprioception, PTS, pain, ROM, and strength (r: 0.332-0.501, 0.197-0.291, 0.340, 0.212-0.508, and 0.236-0.336, respectively). While in the control group, the BBS was correlated with proprioception and strength (r: 0.207-0.379, and 0.212-0.410). In the KOA group, BBS = 54.41+ (0.668*strength) - (0.579*PTS) - (1.141*proprioception) + (1.054* ROM) - (0.339*pain). While in the control group, BBS = 53.85+ (0.441*strength) - (0.677*proprioception). CONCLUSION: Worse proprioception and PTS, smaller ROM, and less strength were detected among older adults with KOA, and their proprioception, PTS, pain, ROM, and strength were all related to balance control. Proprioception had the strongest correlations, followed by ROM, strength, pain, and PTS. Precise KOA rehabilitation programs may be proposed following the sequence of improving the five factors.

Scapular kinematics and muscle activity during Yi Jin Bang exercises.

Introduction: Scapular dyskinesis is commonly associated with subacromial pain syndrome (SAPS). Addressing scapular dyskinesis is widely accepted as an important component of shoulder rehabilitation. Our previous randomized controlled trial showed that Yi Jin Bang (YJB) exercises could effectively manage SAPS, but scapular motions and muscle activity during YJB exercises remain unknown. This study examined scapular kinematics synchronously with scapular muscle activation during YJB exercises. Methods: Thirty healthy participants with no shoulder complaints were enrolled in this study. Three-dimensional (3D) scapular kinematics and electromyography (EMG) activation of the upper trapezius, middle trapezius, lower trapezius, serratus anterior, anterior deltoid, middle deltoid, and posterior deltoid were synchronously measured during nine YJB movements. Results: During all YJB movements, the scapula was upwardly rotated and anteriorly tilted, with more upward rotation and a similar or less anterior tilt than the mean resting scapular angle. Column rotation, arm crossover, shoulder support circle, and armpit support high lift generated more internal rotation than the mean resting scapular angle, with the angles of internal rotation significantly greater than the other five movements (p < 0.001). Regarding EMG activity, all YJB movements elicited low activity (1.42%-19.19% maximal voluntary isometric contraction [MVIC]) from the upper trapezius and posterior deltoid and low to moderate activity (0.52%-29.50% MVIC) from the middle trapezius, lower trapezius, serratus anterior, anterior deltoid, and middle deltoid. Conclusion: YJB exercises could be useful in the middle to later phases of shoulder rehabilitation. For patients with insufficient external rotation, some YJB movements should be prescribed with caution.

Tai Chi practice enables prefrontal cortex bilateral activation and gait performance prioritization during dual-task negotiating obstacle in older adults.

Background: With aging, the cognitive function of the prefrontal cortex (PFC) declined, postural control weakened, and fall risk increased. As a mind-body exercise, regular Tai Chi practice could improve postural control and effectively prevent falls; however, underlying brain mechanisms remained unclear, which were shed light on by analyzing the effect of Tai Chi on the PFC in older adults by means of functional near-infrared spectroscopy (fNIRS). Methods: 36 healthy older adults without Tai Chi experience were divided randomly into Tai Chi group and Control group. The experiment was conducted four times per week for 16 weeks; 27 participants remained and completed the experiment. Negotiating obstacle task (NOT) and negotiating obstacle with cognitive task (NOCT) were performed pre- and post-intervention, and Brodmann area 10 (BA10) was detected using fNIRS for hemodynamic response. A three-dimensional motion capture system measured walking speed. Results: After intervention in the Tai Chi group under NOCT, the HbO2 concentration change value (ΔHbO2) in BA10 was significantly greater (right BA10: p = 0.002, left BA10: p = 0.001), walking speed was significantly faster (p = 0.040), and dual-task cost was significantly lower than pre-intervention (p = 0.047). ΔHbO2 in BA10 under NOCT was negatively correlated with dual-task cost (right BA10: r = -0.443, p = 0.021, left BA10: r = -0.448, p = 0.019). There were strong negative correlations between ΔHbO2 and ΔHbR under NOCT either pre-intervention (left PFC r = -0.841, p < 0.001; right PFC r = -0.795, p < 0.001) or post-intervention (left PFC r = -0.842, p < 0.001; right PFC r = -0.744, p < 0.001). Conclusion: Tai Chi practice might increase the cognitive resources in older adults through the PFC bilateral activation to prioritize gait performance during negotiating obstacles under a dual-task condition.

Proprioceptive Neuromuscular Facilitation Improves Symptoms Among Older Adults With Knee Osteoarthritis During Stair Ascending: A Randomized Controlled Trial.

OBJECTIVE: This study aimed to investigate the effects of a 6-wk proprioceptive neuromuscular facilitation stretching on pain, proprioception, joint range of motion, and joint moments during stair ascending among older adults with knee osteoarthritis. DESIGN: This study is a randomized, controlled, and assessor-blinded trial. Thirty-six older adults with knee osteoarthritis were randomly assigned to the proprioceptive neuromuscular facilitation and the control groups. They received proprioceptive neuromuscular facilitation stretching and health lecture series, respectively, for 6 wks. Final data analysis included 14 participants of the proprioceptive neuromuscular facilitation group and 13 of the control group. Pain score, joint proprioception, range of motion, and joint moments during stair ascending were measured before and after the stretching. Two-way (group by time) analysis of variance with repeated measures was used to evaluate stretching effects. RESULTS: Significant interactions were detected in pain score, joint proprioception, external knee adduction moment, and external knee extension moment. Compared with week 0, the pain score, joint proprioception threshold, and external knee adduction moment decreased, whereas the external knee extension moment increased among older adults in the proprioceptive neuromuscular facilitation group at week 7. CONCLUSIONS: Proprioceptive neuromuscular facilitation could be recommended as one of the clinical treatments for knee osteoarthritis to relieve pain, improve proprioception, and balance load distribution between medial and lateral compartments at the knee.

Effects of running biomechanics on the occurrence of iliotibial band syndrome in male runners during an eight-week running programme-a prospective study.

Iliotibial band syndrome (ITBS) is a common injury that is related to running biomechanics. This study aimed to determine the gait characteristics that easily induce ITBS and explore the gait changes after the occurrence of ITBS. Thirty healthy male recreational runners participated in our study. Amongst them, 15 developed ITBS and comprised the ITBS group; the other 15 were healthy and comprised the control group. All participants underwent two gait trials, namely, before the first day of their running and after eight weeks, during which a force platform and a motion capture system collected biomechanical data. After running, the ITBS group exhibited greater anterior pelvic tilt and hip flexion angle than the control group. The ITBS group showed increased trunk inclination angle, whereas the control group demonstrated lower hip flexion, hip adduction angle and hip abductor moment than those at the beginning of running. Decreasing hip flexion, adduction angle and abductor moment may be a reasonable strategy to avoid the occurrence of ITBS. The occurrence of ITBS may be due to the lack of timely gait adjustment. Excessive trunk inclination and anterior pelvic tilt angle may be risks factor in the development of ITBS during running.

The effect of text-based math task on dynamic stability control during stair descent

Stair descent imposes a significant challenge for dynamic stability among young adults. The effect of a concurrent text-based math task on dynamic stability control remains unclear during stair descent when considering the influence of gait velocity. Twenty-six participants performed three successful stair descent trials under TEXTING or NO-TEXTING conditions at their preferred speed. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. Repeated measures analysis of covariance and Wilcoxon signed rank test were used to analyze the differences between the two different task conditions with gait velocity as a covariate. The outcomes indicated that under TEXTING condition, sagittal margin of stability increased at right-foot-landing; step cadence, double-support percentage, sagittal and frontal joint moment decreased; and sagittal and frontal joint angles were also modified. It is concluded that concurrent TEXTING impaired sagittal and frontal stability control during stair descent despite slowing down the step cadence. Knee and ankle joint adjustment strategies were mainly adopted in response to stability control in the sagittal plane with the interference of TEXTING, whereas the hip joint adjustment strategy was adopted in the frontal plane. In conclusion, texting behaviors on mobile phones should be minimized during stair descent.