Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | Department of Biomedical Engineering | en_US |
| dc.contributor.advisor | Zhang, Ming (BME) | en_US |
| dc.contributor.advisor | Kobayashi, Toshiki (BME) | en_US |
| dc.contributor.advisor | Wong, Wai-chi Duo (BME) | en_US |
| dc.creator | Jor, Abu | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/14384 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | A novel site-specific somatosensory stimulation foot orthosis to improve balance and stability in older adults | en_US |
| dcterms.abstract | Older population is rapidly increasing globally; 1 in 6 people will be 65 or older by 2030, doubling by 2050. Despite improvements in life expectancy, the disability burden remains high because of declines in function and sensory deficits. Age-related diseases contribute over half of the global health burden among adults. The changes in the musculoskeletal and nervous systems because of age can decrease sensory inputs and motor control, increase postural sway and ultimately impair postural balance. This highlights an urgent need for effective interventions to address balance and stability issues in older adults, which are crucial for reducing fall risk and related injuries. | en_US |
| dcterms.abstract | The human foot, as the primary interface between the body and the ground, plays a critical role in providing stability, balance, and propulsion during locomotion. Its tactile perception is essential for maintaining balance and coordination, yet it is often overlooked. The non-hairy glabrous skin of the foot contains numerous sensory mechanoreceptors that detect inputs through mechanical changes such as pressure, touch, stretch, and vibration. They provide crucial somatosensory feedback necessary for postural adjustments. Stimulating these mechanoreceptors with orthotic interventions can offer faster transmission of information about the body position to the central nervous system, facilitating necessary adjustments and enhancing postural control in older adults. | en_US |
| dcterms.abstract | Foot orthoses, including insoles and shoe inserts, are often recommended as orthotic interventions to improve balance, stability, and gait. However, traditional foot orthoses design primarily focus on structural support, with limited research on their impact on balance through sensory feedback and proprioception. Somatosensory stimulation foot orthoses, designed with surface protrusions or textures, have gained attention for their potential to enhance tactile sensitivity and proprioceptive feedback. Despite promising results in improving balance and stability, there remains a research gap in utilizing foot orthoses design features, such as the shape, height, and placement of protrusions, and structure, to maximize their efficacy. Addressing these gaps could offer more targeted orthotic interventions, significantly enhancing balance and stability in older adults, thereby improving overall life quality. | en_US |
| dcterms.abstract | The study aims to design a novel foot orthosis that enhances balance and stability in older adults through site-specific somatosensory stimulation. It outlines five key objectives to achieve this goal. | en_US |
| dcterms.abstract | Objective 1: Review existing evidence on the impact of somatosensory foot orthoses on postural balance and stability, focusing on specific design features such as structure, shape, height, hardness, and positioning of protrusions. In this phase, a systematic review, meta-analysis, and meta-regression were conducted to evaluate the effects of somatosensory foot orthoses on balance and stability in older adults. A comprehensive literature search was conducted across electronic databases to identify studies examining the effects of somatosensory foot orthoses on static and dynamic balance. Eighteen studies with 27 somatosensory foot orthoses conditions were included in the meta-analysis, with balance parameters related to center of pressure (CoP) trajectory reported in at least ten conditions selected for meta-regression analysis. The existing evidence from the systematic review and meta-analysis underscore the importance of specific design features of stimulating protrusion. Our findings showed that somatosensory foot orthoses significantly reduced CoP displacements during standing, particularly for arch-support structures, medium to large size rounded knobs, and site-specific placements. Timed Up and Go test outcomes also improved while other gait measures did not show significant changes although investigated in a fewer number of studies. | en_US |
| dcterms.abstract | Objective 2: Assess whether prefabricated somatosensory foot orthoses with entire surface protruding knobs and arch-support improve postural balance. In this experimental phase, a prefabricated somatosensory foot orthoses and flat foot orthoses were provided to 23 healthy older participants. The postural control measures such as CoP trajectory, spatiotemporal gait, and plantar forces/pressures were assessed while standing with eyes open and closed conditions as well as walking on level, upward, and downward terrains. The participants with these foot orthoses also underwent computerized dynamic posturography assessments. The reductions in CoP displacements were observed with prefabricated somatosensory foot orthoses across certain movement terrains. The improvement in composite equilibrium scores and weight symmetry were also observed. | en_US |
| dcterms.abstract | Objective 3: Identify potential foot sites for tactile stimulation by mapping tactile sensitivity thresholds on the foot. In this cross-sectional study, tactile sensitivity thresholds mapping across 30 distinct foot locations, including plantar, medial, lateral, and dorsal areas were conducted in 46 healthy older adults using Semmes Weinstein monofilaments. Tactile sensitivity thresholds varied by foot locations, with heel, lateral midfoot, and metatarsal heads exhibiting higher sensitivity thresholds. In contrast, medial midfoot, intermedius midfoot, medial and lateral metatarsal bases, and base of navicular exhibited lower thresholds. | en_US |
| dcterms.abstract | Objective 4: Explore dose-response effects of varying protruding knob heights on postural balance, targeting areas of higher tactile sensitivity and lower plantar pressure. This aims to identify optimal protrusion heights that maximize sensory feedback while minimizing discomfort. In this randomized cross-over study, four different foot orthoses including three 3D-printed site-specific somatosensory foot orthoses with short, medium-height, and tall protruding knobs, and one conventional flat foot orthoses were randomly delivered across ten healthy older participants. Postural balance and control were assessed using standardized tests, including CoP trajectory, computerized dynamic posturography, and subjective feedback to explore the effects of varying protrusion heights. Site-specific somatosensory foot orthoses with tall protruding knobs reduced CoP displacements during standing while increased maximum velocity during walking on slopes. However, uniform distribution of tall protruding knobs might produce discomfort at certain areas. | en_US |
| dcterms.abstract | Objective 5: Evaluate the effectiveness of novel site-specific somatosensory foot orthoses with adjusted knob heights compared to conventional flat and placebo foot orthoses without stimulating knobs, utilizing static and dynamic balance and stability measures on varied terrains as well as computerized dynamic posturography in response to perturbations. This phase involved two stage investigations. In the first stage, a randomized crossover trial with 23 healthy older participants. Three distinct foot orthoses including novel site-specific somatosensory foot orthoses, placebo foot orthoses without stimulating knobs and conventional flat foot orthoses were randomly delivered to the participants. The postural control and stability were assessed through standardized tests, including CoP trajectory, spatiotemporal gait, plantar forces/pressures, and subjective feedback regarding tactile perception and satisfaction. The results demonstrated that the novel somatosensory foot orthoses significantly reduced anteroposterior CoP displacements during standing, as well as mediolateral stability at heel strike during walking on upward terrain, compared to both placebo and conventional flat foot orthoses. The somatosensory foot orthoses also led to significant plantar pressure redistribution with reductions in maximum plantar forces at key foot regions during walking on varied terrains. The level of tactile subjective perception was higher at higher tactile sensitivity areas, particularly under the foot arches. The subjective ratings regarding effectiveness to balance control were also higher for the somatosensory foot orthoses. | en_US |
| dcterms.abstract | In the second stage, a randomized controlled trial with 46 older adult participants compared both novel site-specific somatosensory foot orthoses and placebo to flat foot orthoses. Site-specific somatosensory foot orthoses and placebo were assigned to experimental group while flat foot orthoses only assigned to control group. The postural control and stability were assessed through computerized dynamic posturography. The postural equilibrium, weight symmetry, and sway energy to maintain balance in postural adjustments were improved with the novel somatosensory foot orthoses, while increasing latency compared to placebo and flat foot orthoses. | en_US |
| dcterms.abstract | This study advances our understanding of somatosensory stimulation by identifying key design features of protruding knobs that enhance postural balance and stability in older adults. The findings underscore the importance of considering height, shape, and positioning of protrusions, foot orthoses structure, as well as variations in tactile sensitivity across foot regions, when designing orthoses. Notably, a positive dose-response effect was observed with taller knobs at areas of greater tactile sensitivity, suggesting improved postural control, though addressing discomfort through design modifications remains essential. Incorporating site-specific, height-adjusted stimulating knobs may optimize mechanoreceptor activation and postural coordination, broadening clinical applications for individuals with balance impairments. Further longitudinal studies are recommended to refine these designs and ensure their efficacy and comfort in real-world settings. | en_US |
| dcterms.extent | xix, 249 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2026 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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