Older adults adopted more cautious gait patterns when walking in socks than barefoot

Abstract

Walking barefoot or in socks is common for ambulating indoors and has been reported to be associated with increased risk of falls and related injuries in the elderly. This study sought to determine if gait patterns differed between these two conditions for young and older adults. A motion analysis system was used to record and calculate the stride characteristics and motion of the body's center of mass (COM) of 21 young and 20 older adults. For the walking tasks, the participants walked on a smooth floor surface at their preferred speed either barefoot or in socks in a random order. The socks were commercially available and commonly used. The results demonstrated that while walking in socks, compared with walking barefoot, older adults adopted a more cautious gait pattern including decreased walking speed and shortened stride length as well as reduced COM minimal velocity during the single limb support phase. Young adults, however, did not demonstrate significant changes. These findings suggest that walking with socks might present a greater balance threat for older adults. Clinically, safety precautions about walking in socks should be considered to be given to older adults, especially those with balance deficits.

Introduction

Falls and related injuries are major problems facing older adults. Thirty percent of community-dwelling older adults over 65 and 50% of those over 80 years old fall each year [1]. Fall-related injuries, including fractures, head trauma, or soft tissue injuries, are the primary reasons for admission to a hospital or long term care facilities for the elderly [2]. Falls, even without severe injuries, may lead to short- and long-term complications, such as pain, loss of confidence, declined functional capacity, morbidity, or disability [3]. A better understanding of fall risks can help to prevent falls and related injuries and improve the health and life of older adults.

Inappropriate footwear has been identified as one of the extrinsic risk factors of falls for older adults [4]. One key characteristic of footwear that may contribute to falls is the available coefficient of friction [5]. Shoe type or sole materials affect the available friction between the foot and the support surface. A lower available coefficient of friction may not be sufficient to meet the frictional demands of walking and as result, loss of balance or a slip would be more likely to occur [6], [7]. Thus, footwear could affect friction patterns and gait stability, and hence the risk of falls during walking [4], [8], [9].

In regard to footwear, shoes are usually used for outdoor walking for the purposes of aesthetics, protection and propulsion. There exists a large number of studies confirming the association between shoe type and gait patterns of young adults [8], [9]. As for walking barefoot, decreased walking speed, stride length, and hip and knee joint moments, and increased cadence and knee flexion and ankle plantarflexion angle have been found to occur in young adults, compared to walking in shoes [10], [11]. The above changes in gait patterns coincide with cautious gait and suggest that walking barefoot is likely to be associated with greater balance threat than walking in shoes for young adults.

In terms of walking in socks, there have also been studies investigating its effects on foot hygiene for athletes and on reduction of friction to maintain skin integrity for patients with diabetes [12], [13]. As for the comparisons between walking in socks and barefoot, to date only one preliminary study has examined the heel deceleration time, an estimate of slip distance, of a group of healthy young adults and reported that walking barefoot had better slip-resistance than walking with commercially available socks [14]. As to how the stride characteristics differ in these two conditions, the information is scarce.

For the elderly, walking barefoot or in socks is common for reasons of convenience and comfort [4], [15]. Approximately 20–30% of community-dwelling older adults habitually walk barefoot or in socks within their homes [15], [16]. Such a common behavior has been found to be related to increased risk of falls and fall-related severe injuries. Walking barefoot or in socks resulted in a five to ten times increase in the risk of falls for older adults, compared to walking in shoes [17], [18]. And in a previous study, 24% of the 104 fallers were barefoot or only wearing socks while a mere 7% wore athletic footwear at the occurrence of fall-induced hip fracture [19].

While the above findings clearly show that walking barefoot or in socks is associated with increased risk of falls and related injuries, it is not practical to advise older adults who are not used to wearing shoes at home to do so. It would be more helpful, however, if older adults could be advised about the differences in gait characteristics between walking barefoot and in socks in order to make better decisions or take precautions. The purpose of this study was to investigate the differences in gait patterns during walking barefoot and in socks for both young and older adults. It was hypothesized that while younger adults would not be substantially affected, older adults would adopt more cautious gait patterns when walking in socks.