Bridget J. Munro

The Effect of an Individualized Fall Prevention Program on Fall Risk and Falls in Older People: A Randomized, Controlled Trial

Objectives: To determine whether an individualized falls prevention program comprising exercise, visual, and counseling interventions can reduce physiological falls risk and falls in older people.

Optimizing Footwear for Older People at Risk of Falls

Footwear influences balance and the subsequent risk of slips, trips, and falls by altering somatosensory feedback to the foot and ankle and modifying frictional conditions at the shoe/floor interface. Walking indoors barefoot or in socks and walking indoors or outdoors in high-heel shoes have been shown to increase the risk of falls in older people. Other footwear characteristics such as heel collar height, sole hardness, and tread and heel geometry also influence measures of balance and gait. Because many older people wear suboptimal shoes, maximizing safe shoe use may offer an effective fall prevention strategy. Based on findings of a systematic literature review, older people should wear shoes with low heels and firm slip-resistant soles both inside and outside the home. Future research should investigate the potential benefits of tread sole shoes for preventing slips and whether shoes with high collars or flared soles can enhance balance when challenging tasks are undertaken.

Effects of walking surfaces and footwear on temporo-spatial gait parameters in young and older people

This study aimed to investigate the effects of walking surfaces and shoe features on gait variables associated with balance control and the risk of slips and trips in 10 young and 26 older adults. A systematic approach was adopted in which the features of a standard, Oxford-type shoe were individually modified. Subjects walked along a level (control), irregular, and wet walkway in eight randomised shoe conditions (standard, elevated heel, soft sole, hard sole, high-collar, flared sole, bevelled heel and tread sole). Walking velocity, step length, step width, cadence, double-support time, heel horizontal velocity and shoe-floor angle at heel contact, and toe clearance at mid-swing were measured. Older people exhibited a more conservative walking pattern, especially on the irregular and wet surfaces. Compared to the standard shoes, the elevated heel shoes elicited increased double-support time, heel horizontal velocity at heel strike and toe clearance. On the wet surface, the soft sole shoes led to shorter steps and a flatter foot landing, gait adaptations which are associated with perceptions of shoe/surface slipperiness. Increasing collar height led to greater double-support time and step width. The results indicate that shoes with elevated heels or soft soles impair walking stability in older people, especially on wet floors, and that high-collar shoes of medium sole hardness provide optimal stability on level dry, irregular and wet floors.

The Feet of Overweight and Obese Young Children: Are They Flat or Fat?

Objective: The purpose of this study was to determine whether the flat feet displayed by young obese and overweight children are attributable to the presence of a thicker midfoot plantar fat pad or a lowering of the longitudinal arch relative to that in non‐overweight children.

Foot pain, plantar pressures, and falls in older people: a prospective study.

OBJECTIVES: To determine whether foot pain and plantar pressure are associated with falls in community‐dwelling older adults.

ISB Clinical Biomechanics Award 2009: Toe weakness and deformity increase the risk of falls in older people

BACKGROUND Hallux valgus and lesser toe deformities are highly prevalent foot problems in older people. One factor contributing to the development of these toe deformities is reduced toe flexor strength. As adequate toe flexor strength is also crucial in maintaining balance, it was hypothesised that poor toe flexor strength and toe deformities would increase the risk of falls in community-dwelling older people. METHOD The feet of 312 men and women aged 60-90 years were assessed for the presence of lesser toe deformities and hallux valgus. Hallux and lesser toe flexor strength were assessed using an emed AT-4 pressure platform and novel test protocol. Participants were then followed prospectively to determine their falls incidence over 12 months. FINDINGS During the 12 month follow-up, 107 (35%) participants experienced a fall. Compared to non-fallers, fallers displayed significantly less strength of the hallux (11.6 (SD 6.9) versus 14.8 (SD 7.8)% BW, P<0.01) and lesser toes (8.7 (SD 4.7) versus 10.8 (SD 4.5)% BW, P<0.01), and were more likely to have hallux valgus (relative risk [RR]=2.36; 95% CI=1.03-5.45; P<0.01) and lesser toe deformity (RR=1.32; 95% CI=1.04-1.69; P<0.01). INTERPRETATION Reduced toe flexor strength and the presence of toe deformities increase the risk of falling in older people. To reduce this risk, interventions designed to increase strength of the toe flexor muscles combined with treatment of those older individuals with toe deformities may be beneficial.

Effects of Shoe Characteristics on Dynamic Stability When Walking on Even and Uneven Surfaces in Young and Older People

OBJECTIVE To systematically investigate the effects of various shoe features (sole hardness, heel height, heel collar height, tread pattern) on dynamic balance control and perceptions of comfort and stability in young and older people walking over even and uneven surfaces. DESIGN A mixed-design 3-way repeated measures with age as a between-subjects factor and surface and shoe conditions as within-subjects factors. SETTING Gait laboratory. PARTICIPANTS Young adults (n=11) and community-dwelling older adults (n=15). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Center of mass (COM)-base of support (BOS) margins, vertical and braking loading rates, and subjective ratings of perceived shoe comfort and stability. RESULTS Overall, compared with the standard shoes, the soft sole shoes led to greater lateral COM-BOS margin (P<.001), whereas the elevated heel shoes caused reductions in posterior COM-BOS margin (P=.001) and in vertical and braking loading rates (both, P<.001). Subjects rated the elevated heel shoes as significantly less comfortable (P<.001) and less stable (P<.001) than the standard shoes. Only the young subjects perceived the soft-sole shoes to be less stable than the standard shoes (P=.003). CONCLUSIONS Both young and older subjects adopted a conservative walking pattern in the elevated heel shoes and exhibited impaired mediolateral balance control in the soft-sole shoes. In contrast, increased sole hardness (above that found in a standard shoe), a tread sole, and a raised collar height did not improve walking stability in either group. It is concluded that shoes with elevated heels or soft soles should not be recommended for older people and that a standard laced shoe with a low collar and a sole of standard hardness with or without a tread provides optimal dynamic stability when walking on even and uneven surfaces.

Effects of Footwear Features on Balance and Stepping in Older People

Background: Although footwear has been linked to falls in older people, it remains unclear as to which shoe features are beneficial or detrimental to balance in older people. Objective: To systematically investigate how footwear features affect balance and stepping in older people. Methods: 29 community-dwelling people (mean (SD) age, 79.1 (3.7) years) undertook tests of postural sway, maximal balance range, coordinated stability and choice-stepping reaction time in a standard shoe and seven other shoes that differed from the standard shoe in one feature only, namely: elevated heel (4.5 cm), soft sole, hard sole, flared sole, bevelled heel, high heel-collar and tread sole. Results: Repeated-measures ANOVA with simple contrasts revealed significantly increased sway in the elevated heel versus the standard shoe condition (p < 0.05). A footwear performance index based on the sum of z-scores across three tests (sway, coordinated stability and choice-stepping reaction time) normalized to the standard condition indicated that the elevated heel was most detrimental to balance (p < 0.05) whereas a high heel-collar and a hard sole showed trends towards being beneficial. Conclusion: An elevated heel of only 4.5 cm height significantly impairs balance in older people. The potential benefits of wearing shoes with a hard sole or a high heel-collar on balance in older people warrant further research in ambulatory tasks.

Gait, balance and plantar pressures in older people with toe deformities

Older people with toe deformities have been identified as having an increased risk of falling. Little is known, however, about the biomechanical changes that might contribute to this increased risk. Therefore, the purpose of this study was to determine whether older people with hallux valgus and lesser toe deformities displayed different gait, balance and plantar pressure characteristics compared to individuals without toe deformities. The presence of hallux valgus and lesser toe deformities were assessed for 312 community-dwelling older men and women. Spatiotemporal gait parameters were measured using the GAITrite(®) system, postural sway was assessed on two surfaces using a sway-meter and dynamic plantar pressure distribution was measured using an Emed-AT4 pressure plate. The results indicated that, although there were no effects of toe deformities on spatiotemporal gait characteristics or postural sway, older people with hallux valgus (n=36) and lesser toe deformities (n=71) were found to display altered forefoot plantar pressure patterns. These findings suggest that toe deformities alter weight distribution under the foot when walking, but that the relationship between toe deformities and falls may be mediated by factors other than changes in spatiotemporal gait parameters or impaired postural sway.

Does excess mass affect plantar pressure in young children

OBJECTIVE To determine the effects of overweight and obesity on plantar pressures generated by pre-school children during gait. METHODS Dynamic plantar pressure variables were measured for 17 overweight/obese children (age = 4.4 +/- 10.8 years; height = 1.08 +/- 0.1 m; body mass index (BMI) = 18.5 +/- 1.3 kg x m(-2)) and 17 age, gender and height matched non-overweight peers (age = 4.4 +/- 0.7 years, height = 1.06 +/- 0.1 m, BMI = 15.7 +/- 0.7 kg x m(-2)). RESULTS When walking, the overweight/obese children displayed significantly larger contact areas and generated significantly larger forces on the plantar surface of their total foot, heel, midfoot and forefoot compared to the non-overweight children. Despite generating these higher forces over larger contact areas, the overweight/obese children displayed significantly higher peak pressures, force-time integrals and pressure-time integrals in the midfoot compared to their leaner counterparts. CONCLUSIONS Although the overweight/obese children displayed greater midfoot contact, this increased contact area was not sufficient to compensate for the high forces generated during walking, resulting in them experiencing higher midfoot plantar pressures relative to the non-overweight children. The overweight/obese children also experienced significantly higher force-time and pressure-time integrals than their leaner counterparts, suggesting that their midfoot may be exposed to increased stress and, in turn, vulnerable to bony fatigue and soft tissue damage. The impact of these greater plantar pressure variables on foot discomfort and physical activity levels of these young overweight/obese children as they develop into adults requires further investigation.