As people age, everyday tasks become more fatiguing. Current research does not yet show how physical activity affects the ability to withstand fatigue. The purpose of this research is to quantify and compare muscle fatigue in response to prolonged walking in younger and older males and females. The older adults are categorized as being active, healthy, or impaired. 

The hypothesis is that there are differences expected between men and women, as well as the younger and older groups, and  these differences will be mitigated by physical activity levels. Differences in sex may be related to variance in muscle strength. 

Older adults completed maximum knee extensor testing before and after a 30-minute treadmill walk at their preferred walking pace. Maximum knee testing was performed using dynamometry at 0 degrees per second (dps), 120 dps, and 240 dps. The 30 minute treadmill walk included 1 minute challenge periods with 3% incline increases at minute 7, 14, and 21. Outcome measures included changes in torque and power (ratio of the post- and pre-walk measurements) and will be expressed as a percentage of baseline. 

Significant differences across the groups could explain higher risk for falls and musculoskeletal diseases. The literature shows that aging is associated with redistribution of muscle mechanics, and that physical activity can help mitigate aging effects. Reducing levels of muscle fatigue during everyday tasks for older adults promotes better health outcomes as well as a higher level of independence, which improves quality of living.

Background: Adolescent sport participation brings many benefits, but can negatively influence aspects of health that are especially vulnerable during this developmental stage. Sleep health impacts both performance anxiety and mental burnout, which are directly related to the demands of daily practices, competitions, and overall athletic performance. 

Purpose: To analyze device-measured sleep health metrics and their relation to levels of performance anxiety and mental burnout in adolescent student athletes. 

Methods: Participants included middle and high school student athletes ages 11 to 18 participating in at least one competitive sport season, including clubs or teams outside of school. Students completed a questionnaire assessing anxiety and burnout symptoms. Additionally, to estimate activity and sleep metrics, students wore an activity monitor on their non-dominant wrist and completed a log for one week. 

Results: Summary statistics will be calculated for each sleep health variable. Multiple regression models will be run, with performance anxiety as the outcome and each sleep health metric as an independent variable. A second set of linear regression models will be run with mental burnout as the outcome and each sleep health metric as an independent variable. We predict that poor sleep health metrics will be associated with higher levels of performance anxiety and mental burnout in adolescent student athletes.

Background: The World Health Organization (WHO) has 24-hour movement behavior guidelines for children 3-5 years of age that includes monitoring physical activity, sleep and limited sedentary time. Despite these regulations, there are disparities in the ability of caregivers and children to adhere to these conditions due to socioeconomic factors. Understanding more about the relations between sociodemographic factors and children’s 24-hour movement behaviors can help determine strategies to promote awareness about these gaps and encourage action.    

Purpose: To identify the proportion of western Massachusetts preschool children who meet the WHO 24-hour movement behavior guidelines and to determine the associations between socioeconomic factors and meeting these guidelines.

Methods: Used a cross-sectional design study where participants were preschool children, ages 3-5 residing in Western Massachusetts. Adult caregivers shared sociodemographic information (highest household education, caregiver income and housing type) and children’s screen time via an online questionnaire. Children wore a GENEActiv activity monitor on their non-dominant wrist for one week to estimate 24-hour movement behaviors and caregivers completed a daily activity and sleep log. 

Results: Descriptive statistics will be calculated to determine the proportion of participants meeting the WHO guidelines and the association with socioeconomic status. Correlations will be examined with logistic regression models.

Conclusion: Households with lower income and education will be more likely to have limited access to materials and the resources to promote 24-hour behaviors in children therefore having poor WHO guideline adherence. Our findings can help identify and better understand potential health disparities and areas where additional support is needed for intervention approaches. 

Background: Meeting 24-hour movement behaviors (physical activity, sleep, and sedentary time) are linked to positive health benefits in young children. However, limited research is available of the proportions of preschool-aged children meeting these behavior guidelines and if the proportions vary based upon sex on a regional level. 

Purpose: To determine the proportion of preschoolers that meet 24-hour movement behavior guidelines for children under five in Western Massachusetts and assess if proportions vary based upon sex differences. 

Methods: We used a cross-sectional study of preschool aged children (3-5 yrs old) composed of two assessment phases. The first phase included a collection of child anthropometric measures. The second phase included monitoring the child’s 24-hour movement behaviors levels for one week via a wrist-worn GENEActiv activity monitor. This phase included a caregiver questionnaire and a daily log of their child’s movement behaviors. 

Planned Analysis: First, the proportion of the sample meeting the full 24-hour movement behavior guidelines, as well as each individual behavior recommendation will be calculated. Second a binary logistic regression will be used to examine whether the sex is associated with meeting the guidelines.

Implications: These findings will identify the proportion of young children from Western Massachusetts in our sample who are meeting the WHO guidelines, and this varies by sex. We anticipate that our findings will provide preliminary information to help identify needs and tailor future movement and sleep promotional approaches in this region. 

BACKGROUND: Children’s 24-hour movement behaviors (physical activity, sedentary behavior, and sleep) during early childhood influence healthy development. Variations in 24-hour movement behaviors may lead to differences in health between children with developmental differences and those with typical development. Nevertheless, little research has examined these differences using a holistic 24-hour movement approach in preschool-aged children.

PURPOSE: To identify the levels and proportions of preschool children with and without developmental differences who meet the global 24-hour movement guidelines, and to determine if there are differences between these groups. 

METHODS: With a cross-sectional design, in preschool children, movement behaviors were measured using wrist-based activity monitors worn for one week, and caregivers completed a survey and daily logs. The proportion of meeting the overall 24-hour movement behavior guidelines was determined, as well as the proportion meeting each behavior recommendation. 

RESULTS: Descriptive statistics were used for the characteristics and adherence to the guidelines. To explore group differences in the levels of 24-hour behaviors, independent t-tests were used. To examine differences around meeting the guidelines, we used Fisher’s exact tests. We predicted that children with developmental differences would have higher sedentary behavior, lower physical activity, and a lower proportion meeting the combined movement guidelines compared to those without developmental differences.  

CONCLUSIONS: This study may help identify disparities related to developmental considerations, which may help inform intervention targets in preschool children.

Introduction 

Stroke is a leading cause of disability in the United States, with more than 800,000 cases annually. Approximately 55% of chronic stroke survivors exhibit persistent gait asymmetries. Altered ground reaction forces during weight acceptance and push-off contribute to impaired gait performance and can inform rehabilitation strategies. Previous experiments report that asymmetric surface stiffness walking can induce changes in weight bearing in healthy individuals, but the extent to which these results transfer to overground walking is unknown. This study examines whether asymmetric surface stiffness walking induces weight bearing asymmetries that transfer to overground walking.

Methods 

5 healthy individuals participated in this study. Participants first completed a speed test on a 12.5 m overground walkway to determine preferred walking speed, followed by 3 baseline walking trials. Participants then completed a 12-minute walking trial on the AdjuSST [4], including a 2-minute acclimation period and 10 minutes of asymmetric stiffness walking, with one belt set to rigid (300 kN/m) and the other to 15 kN/m. Treadmill speed was set to 15% below preferred overground speed. A final 5-minute overground walking trial was completed to assess aftereffects.

Results 

Immediately following asymmetric surface stiffness walking, vertical ground reaction force (vGRF) increased in the limb exposed to low stiffness relative to baseline, presenting as a vGRF asymmetry. 

Conclusion 

These findings indicate that asymmetric stiffness walking has the capacity to induce short-term changes in midstance and push-off vGRF symmetry, and that these changes partially transfer to overground walking, which is important for any potential gait rehabilitation intervention.

Accurate measurement of human movement and joint angles is essential in clinical and research settings. Optical motion capture (OMC) systems are considered the gold standard for these measurements, however, they are expensive, complex, and require highly trained staff to operate. This study evaluated the validity of Moveo Explorers proprietary joint angle approximation algorithm by comparing lower extremity joint angle approximations from wearable inertial measurement units (IMU) with joint angle approximations from OMC systems during walking gait in healthy adults. 

Data were collected from 19 healthy individuals aged 18-30. Participants were instrumented with IMUs (Opal V2; APDM) and reflective motion capture (Qualysis, Motion Analysis) markers from their waist to their feet and completed a 5 minute treadmill walking trial at their preferred speed. Data from both systems were collected simultaneously. 

Validity of wearable IMU joint angle approximations was assessed using intraclass correlation coefficients (ICCs) for each body side (left, right) and joint (hip, knee, ankle) with 95% confidence intervals. ICCs for the right and left hip were 0.995(0.966-0.999) and 0.985(0.735-0.998) and the right and left knee were 0.97(0.795-0.996) and 0.96(0.733-0.994), respectively, indicating excellent agreement. The right and left ankle ICCs were 0.845(0.175-0.978) and 0.856(0.134-0.979), indicating good agreement. 

These findings support the validity of Moveo Explorers proprietary algorithm for lower extremity joint angles during gait in healthy adults, suggesting this wearable IMU system is a practical alternative to OMC. Improved accessibility to accurate, portable motion analysis systems may enhance clinical decision making and support individualized rehabilitation interventions across different settings. 

Gait analysis is used in clinical research to evaluate lower extremity movement patterns associated with walking. Foot strike and toe-off angles are key kinematic variables that reflect ability to avoid obstacles across walking environments. While overground walking is considered the clinical gold standard, laboratory gait analyses approaches vary between overground and treadmill surfaces. Further, clinical gait analyses are typically completed via subjective observation, while the laboratory gold standard is with optical motion capture. The purpose of this study was to compare foot strike and toe-off angles during overground and treadmill surfaces to determine if ankle gait kinematics are similar between treadmill and overground surfaces. 

Participants completed an overground and treadmill walking condition. Bilateral averaged ankle  foot strike and toe-off angles were calculated across the full walking condition. Intraclass correlation coefficients (ICC) were computed to assess measurement reliability between surfaces.

Results indicated that foot strike angles were larger for overground walking (L: 29.07°±3.72, R: 28.29°±5.12) than for treadmill walking (L: 25.15°±4.22, R: 24.80°±4.40). Similarly, toe-off angles were larger overground (L: 40.12°±3.87, R: 40.96°±2.94) than on the treadmill (L: 38.18°±4.73, R: 39.35°±4.13). Statistical analysis revealed an ICC of 0.928 (LB CI: -0.015, UB CI: 0.995), indicating a measurement validity rating of ‘excellent’. These findings suggest small but consistent kinematic differences between walking environments.

Consistent with previous research (Riley et al., 2007), treadmill walking produces gait mechanics that are comparable to overground walking, though minor differences in joint angle approximations may occur. Clinically, this supports the use of published treadmill-based ankle kinematics for clinical comparison.

Despite Ankle Injuries being one of the most common injuries inflicted on dancers, the relationship between ankle strength, flexibility, and balance still remains a lack of definition.This research study aims to determine how these factors interact with each other and whether a specific combination of strength and flexibility can predict better balance and therefore lower ankle injury risk in dancers. To investigate these questions, the study will assess dancers using goniometric measurements of ankle range of motion (dorsiflexion, plantar flexion, inversion, and eversion), handheld dynamometry for ankle strength, and a standardized balance assessment known as the Star Excursion Balance Test. Participants will also complete a pre screening survey, along with a demographic and injury‑history survey to identify if the participant is eligible and if any patterns can be found between past injuries and current physical measures. Data will be analyzed using a multiple regression to determine whether ankle strength and flexibility are predictors of balance performance and whether these variables differ between dancers with and without prior ankle injuries.

The research was inspired by the high prevalence of ankle sprains in dance populations and the lack of consensus on whether increased flexibility enhances performance or increases vulnerability to injury. Understanding how these components interact can have a positive effect on injury prevention, dance training, and rehabilitation. By identifying the most effective combination of strength and flexibility for optimal balance, this research may guide evidence‑based conditioning programs that reduce injury risk and support long‑term dancer health and performance.