Size of the abductor hallucis muscle in older women with hallux valgus

Abstract of paper that was presented at the 4th Congress of the International Foot and Ankle Biomechanics (i-FAB) Community Busan, Korea, 8-11 April 2014

Obese older adults suffer foot pain and foot-related functional limitation

There is evidence to suggest being overweight or obese places adults at greater risk of developing foot complications such as osteoarthritis, tendonitis and plantar fasciitis. However, no research has comprehensively examined the effects of overweight or obesity on the feet of individuals older than 60 years of age. Therefore we investigated whether foot pain, foot structure, and/or foot function is affected by obesity in older adults. Three hundred and twelve Australian men and women, aged over 60 years, completed validated questionnaires to establish the presence of foot pain and health related quality of life. Foot structure (anthropometrics and soft tissue thickness) and foot function (ankle dorsiflexion strength and flexibility, toe flexor strength, plantar pressures and spatiotemporal gait parameters) were also measured. Obese participants (BMI \u3e30) were compared to those who were overweight (BMI = 25-30) and not overweight (BMI \u3c25). Obese participants were found to have a significantly higher prevalence of foot pain and scored significantly lower on the SF-36. Obesity was also associated with foot-related functional limitation whereby ankle dorsiflexion strength, hallux and lesser toe strength, stride/step length and walking speed were significantly reduced in obese participants compared to their leaner counterparts. Therefore, disabling foot pain and altered foot structure and foot function are consequences of obesity for older adults, and impact upon their quality of life. Interventions designed to reduce excess fat mass may relieve loading of the foot structures and, in turn, improve foot pain and quality of life for older obese individuals

Fat flat frail feet: how does obesity affect the older foot

The prevalence of obesity is rising throughout the world at an alarming rate, and the elderly are no exception with 15% of men and 28% of women aged over 60 years considered to be obese [1]. Overweight and obesity have been shown to negatively affect foot structure and function in both children [2] and adults [3]. These structural changes appear to be associated with increased foot discomfort whereby overweight children have been found to report foot pain significantly more often than their leaner counterparts [4]. As feet are our base of support during most weight-bearing activities, it is postulated that increased foot pain could act as a deterrent for obese individuals to participate in physical activity and, in turn, perpetuate the cycle of obesity. For this reason compromised foot structure and foot pain associated with obesity is deemed a major health issue for children. However, whether these negative effects associated with childhood obesity persist in the elderly foot has not been comprehensively investigated. Therefore, the purpose of this study was to determine the effects of obesity on foot structure and function, and the foot pain experienced by older adults

Size of the abductor hallucis muscle in older women with hallux valgus

Toe deformities are highly prevalent in older people with up to 74% of older men and women having some degree of hallux valgus [1]. Despite the well documented hypotheses that atrophied, or weak toe flexor muscles are associated with the formation of toe deformities [2], there has been little evidence to support this theory. Only one study has directly compared the toe flexor strength of individuals with toe deformities to those without, revealing that older people with hallux valgus have reduced hallux strength compared to those without the deformity [3]. Therefore, to further investigate the pathomechanics of hallux valgus, this study aimed to determine whether the size of the abductor hallucis muscle differed in older women with and without hallux valgus deformity

Effects of age on strength and morphology of toe flexor muscles

Study Design: Cross-sectional. 27 Objective: To compare the strength and size of the toe flexor muscles of older adults relative 28 to their younger counterparts. 29 Background: Age related muscle atrophy is common in lower limb muscles and we therefore 30 speculated that foot muscles also diminish with age. However, there is a paucity of literature 31 characterizing foot muscle strength and morphology, and any relationship between these two, 32 in older people. 33 Methods: Seventeen young adults with a normal foot type were matched by gender and BMI 34 to 17 older adults with a normal foot type, from an available sample of 41 young (18-50 35 years) and 44 older (60+ years) adults. Among the matched groups (n=34), muscle thickness 36 and cross-sectional area (CSA) for five intrinsic and two extrinsic toe flexor muscles were 37 obtained using ultrasound. Toe strength was assessed using a pressure platform. Differences 38 in toe flexor strength and muscle size between the young and older matched groups were 39 determined using ANCOVA (controlling for height). Correlations between strength and size 40 of the toe flexor muscles of the pooled group (n=34) were also calculated. 41 Results: Toe strength and the thickness and CSA of most foot muscles and were significantly 42 reduced in the older adults (P<0.05). Hallux and toe flexor strength were strongly correlated 43 with the size of the intrinsic muscles toe flexor muscles. 44 Conclusion: The smaller foot muscles appear to be affected by sarcopenia in older adults. 45 This could contribute to reduced toe flexion force production and affect the ability of older 46 people to walk safely. Interventions aimed at reversing foot muscle atrophy in older people 47 require further investigation

A protocol to prospectively assess risk factors for medial tibial stress syndrome in distance runners

Abstract Background Medial tibial stress syndrome (MTSS) is a lower leg injury with a reported incidence rate of up to 35% in active individuals. Although numerous prospective studies have tried to identify risk factors for developing MTSS, managing the syndrome remains difficult. One risk factor yet to be extensively explored in MTSS development is reduced lower leg girth. Further investigation of reduced lower leg girth is required due to the important role lower leg musculature plays in attenuating ground reaction forces during the gait cycle. Therefore, the primary aim of this study is to ascertain whether lower leg muscle morphology and function contribute to the development of MTSS. Our ultimate aim is to identify potential risk factors for MTSS that can be targeted in future studies to better manage the injury or, preferably, prevent individuals developing MTSS. Methods This study will be prospective in design and will recruit asymptomatic distance runners. All participants will be tested at base line and participants will have their training data longitudinally tracked over the following 12 months to assess any individuals who develop MTSS symptoms. At base line, outcome measures will include bilateral measures of lower limb anthropometry; cross sectional area (CSA) and thickness of the tibialis anterior, peroneals, flexor digitorum longus, flexor hallucis longus and thickness of soleus, medial and lateral head of gastrocnemius. Tibial bone speed of sound, ankle dorsiflexion range of motion, strength of the six previously described muscles, foot alignment and ankle plantar flexor endurance will also be assessed. Participants will also complete a treadmill running protocol where three-dimensional kinematics, plantar pressure distribution and electromyography data will be collected. Discussion This study will aim to identify characteristics of individuals who develop MTSS and, in turn, identify modifiable risk factors that can be targeted to prevent individuals developing this injury

Reliability of ultrasound to measure morphology of the toe flexor muscles

Measuring the strength of individual foot muscles is very challenging; however, measuring muscle morphology has been shown to be associated with strength [1]. A reliable method of assessing foot muscle atrophy and hypertrophy would therefore be beneficial to researchers and clinicians. Real-time ultrasound (US) is a non-invasive, objective and inexpensive method of assessing muscle morphology and has been employed widely to quantify cross-sectional area (CSA) and linear dimensions of larger muscles (e.g. quadriceps, triceps surae). Few studies, however, have determined its ability to measure the small muscles of the foot and ankle. This study aimed to determine whether US is a reliable tool to measure the morphology of the toe flexor muscles

Are toe weakness and deformity associated with falls in older people

Hallux valgus and lesser toe deformities are highly prevalent foot problems in older adults, affecting up to 74% of this population. One suggested cause of these toe deformities is inadequate strength of the intrinsic flexor muscles of the toes [1]. Adequate toe flexor strength is essential to control body weight shifts, propel the body during gait and assist in shock absorption during repeated impacts. Furthermore, a previous study using a qualitative measure of toe flexor strength reported associations between poor toe flexor strength and poor performance in balance and functional tests in elderly people [2]. Of further concern, in a sample of retirement home dwellers, fallers were more likely to have severe hallux valgus and fail a clinical test of toe-flexor strength more often than non-fallers [3]. However, this association has not been investigated in community-dwelling older people or assessed using a quantitative method of toe flexor strength. Therefore, the purpose of this study was to determine whether toe flexor strength or the presence of hallux valgus or lesser toe deformities were associated with the risk of falling in older community dwelling adults

Relationship between plantar pressures, physical activity and sedentariness among preschool children

It has been speculated that high plantar pressures might cause foot pain and discomfort which, in turn, may discourage children from being physically active and result in them spending more time in sedentary activities. The purpose of this study was to determine whether plantar pressure distributions generated by preschool children were correlated with objectively measured time spent in physical activity and sedentary behaviour. Dynamic plantar pressures were measured for 33 preschool children (age = 4.3±0.6 years; height = 1.06±0.1 m; mass = 18.4±2.9 kg; 17 boys) as they walked across an emed AT-4 pressure platform. Physical activity was objectively assessed using MT ActiGraph accelerometers. Total physical activity (counts per minute), percentage of time spent in moderate-to-vigorous physical activity (MVPA), light activity and sedentary behaviour were then calculated. Peak pressures across the heel were found to significantly correlate with total physical activity (r =−0.53; p = 0.03) and time in MVPA (r =−0.47; p = 0.05) in boys. Similarly, the correlation data suggested that girls who generated higher peak pressures in the toe region spent more time in sedentary behaviour (r = 0.53; p = 0.04). As high plantar pressures appear to be a potential negative correlate of physical activity and sedentary behaviour, it is recommended that further research be conducted to design, test and evaluate the potential of interventions to reduce plantar pressures in inactive children so they can enjoy the benefits associated with participating in a more active lifestyle