Browsing by Author "Arena, Sara L."

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    Differences in Balance and Limb Loading Symmetry in Postpartum and Nulliparous Women During Childcare Related Activities
    Libera, Theresa L. (Virginia Tech, 2024-10-02)
    Every year, over 3.5 million women give birth in the United States, with about 67.9% delivering vaginally. Over 80% of postpartum (PP) women experience chronic pain in the pelvis, lower back, hip, and legs at 24 weeks after birth, and 20% continue to experience these issues 3 years later. PP women often face pelvic instability and weakness, which disturb balance and lead to asymmetric loading in the pelvis and legs. This imbalance makes daily tasks, such as lifting and carrying a car seat during childcare, more difficult, and increases the risk of chronic pain and injury. This study aimed to explore how different groups – PP and nulliparous (NP) women – and different ways of holding a car seat while standing – no holding, symmetrical holding with two hands in front, and asymmetrical holding with one arm by the side – affect balance and limb loading symmetry. Results showed that postpartum women struggled more with balance as the task became more challenging, with asymmetrical holding showing large differences between groups. PP women also exhibited greater asymmetric limb loading compared to NP women with asymmetrical holding creating the greatest level of asymmetric limb loading. The study also aimed to explore how the two groups – PP and NP – and the different ways of lifting a car seat – symmetrically and asymmetrically – affect balance and limb loading. Both groups had more asymmetric limb loading and worse balance with asymmetrical lifting, though NP women showed larger movements during asymmetrical lifting, likely reflecting the movement of the body during the condition. These results highlight the importance to further research balance and limb loading in PP compared to NP women. Understanding whether pelvic instability and weakness may contribute to differences in balance and limb loading is crucial as it may help explain how and why postpartum women face higher risk of injury and chronic pain. Ultimately, such work may find ways to improve postpartum health during daily activities.
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    Differences in Load Symmetry of the Lower Extremities in Postpartum Women During Daily Tasks and Childcare Loading Conditions
    Henry, Alison Lohr (Virginia Tech, 2024-06-27)
    In 2021, over three and a half million women entered the postpartum period in the United States [1]. Despite their prevalence, postpartum health is a largely overlooked area. After delivery, 25% of women within this population experience lumbopelvic or pelvic pain during the typical postpartum period [3], up to 8 weeks post-delivery, and research has found these women may continue to experience pain years after delivery [4]. Persistent pelvic region pain in postpartum women may result in lower limb load asymmetry. Additionally, external loading from carrying a child may alter the degree of asymmetric loading that exists in the lower limbs. Therefore, the first purpose of this study was to investigate the effect of daily tasks on lower extremity load symmetry using metrics that have successfully identified load asymmetry in other populations. Load symmetry was found to differ between task, with the largest asymmetry occurring between limbs during the sit-to-stand task for the peak impact force (PIF = 9.08% symmetry) and during the stair descent task for the average loading rate (ALR = 15.43% symmetry). The increase in asymmetry during these tasks may be attributed to increased muscle activation and force production. The second purpose of this study was to investigate the effect of an external child load on lower extremity load asymmetry during a 14-meter level walking task. A significant increase was found between the no load and both child load conditions for PIF and ALR (p <0.001 for both metrics). No statistically significant differences in symmetry were found between carrying the child centrally in a carrier and carrying on one side of the body without a carrier. The lack of difference in asymmetry during child carrying conditions may indicate mothers naturally compensate for the external child load as both ALR and PIF values increased during these conditions, but asymmetry was not impacted. Our results indicate the need to continue to examine different carrying conditions in postpartum women to better understand risk factors for pain or injury and provide evidence-based recommendations for postpartum activity progression.
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    Tripping Elicits Earlier and Larger Deviations in Linear Head Acceleration Compared to Slipping
    Arena, Sara L.; Davis, Julian L.; Grant, John Wallace; Madigan, Michael L. (PLOS, 2016-11-01)
    Slipping and tripping contribute to a large number of falls and fall-related injuries. While the vestibular system is known to contribute to balance and fall prevention, it is unclear whether it contributes to detecting slip or trip onset. Therefore, the purpose of this study was to investigate the effects of slipping and tripping on head acceleration during walking. This information would help determine whether individuals with vestibular dysfunction are likely to be at a greater risk of falls due to slipping or tripping, and would inform the potential development of assistive devices providing augmented sensory feedback for vestibular dysfunction. Twelve young men were exposed to an unexpected slip or trip. Head acceleration was measured and transformed to an approximate location of the vestibular system. Peak linear acceleration in anterior, posterior, rightward, leftward, superior, and inferior directions were compared between slipping, tripping, and walking. Compared to walking, peak accelerations were up to 4.68 m/s2 higher after slipping, and up to 10.64 m/s2 higher after tripping. Head acceleration first deviated from walking 100-150ms after slip onset and 0-50ms after trip onset. The temporal characteristics of head acceleration support a possible contribution of the vestibular system to detecting trip onset, but not slip onset. Head acceleration after slipping and tripping also appeared to be sufficiently large to contribute to the balance recovery response.