The effect of dual tasking on foot biomechanics in people with functional ankle instability

Background: Some cases of repeated inversion ankle sprains are thought to have a neurological basis and are termed functional ankle instability (FAI). In addition to factors local to the ankle, such as loss of proprioception, cognitive demands have the ability to influence motor control and may increase the risk of repetitive lateral sprains. Objective: The purpose of this study was to investigate the effect of cognitive demand on foot kinematics in physically active people with functional ankle instability. Methods: 21 physically active participants with FAI and 19 matched healthy controls completed trials of normal walking (single task) and normal walking while performing a cognitive task (dual task). Foot motion relative to the shank was recorded. Cognitive performance, ankle kinematics and movement variability in single and dual task conditions was characterized. Results: During normal walking, the ankle joint was significantly more inverted in FAI compared to the control group pre and post initial contact. Under dual task conditions, there was a statistically significant increase in frontal plane foot movement variability during the period 200ms pre and post initial contact in people with FAI compared to the control group (p<0.05). Dual task also significantly increased plantar flexion and inversion during the period 200ms pre and post initial contact in the FAI group (p<0.05). Conclusion: participants with FAI demonstrated different ankle movement patterns and increased movement variability during a dual task condition. Cognitive load may increase risk of ankle instability in these people

The effect of three different insoles on ankle movement variability during walking in athletes with functional ankle instability.

Increased ankle movement variability has been reported in people with functional ankle instability (FAI). The purpose of this study was to investigate the effect of textured insole, lateral wedge, and textured lateral wedge insole on ankle movement variability during walking in athletes with FAI. Twenty-one athletes diagnosed with FAI participated in this before-after study. Kinematic data were collected during four conditions (5 repeated trials per condition): (1) flat ethylene-vinyl acetate (EVA) insole, (2) textured flat EVA insole, (3) prefabricated lateral heel and sole wedge insole, and (4) textured lateral heel and sole wedge. The analysis of ankle movement variability was conducted during stance phase and 200 ms before initial contact to 200 ms after initial contact. The coefficient of multiple correlations (CMC) was calculated to investigate pattern variability and intraclass correlation (ICC) was used to investigate variability at the points of interest. In terms of pattern variability, wearing textured lateral wedge increased CMC compared to other insoles. However, statistically significant differences were observed only in the frontal plane during stance phase ( < 0.05). In terms of variability at the points of interest, in the frontal plane and in all points of interest, wearing textured lateral wedge increased ICC compared to other insoles. The effects of other insoles on ankle movement variability were inconsistent. The results of this study showed that textured insole has the potential to decrease variability and the use of texture with lateral wedge may more improve variability in athletes with FAI

The effect of stroke on foot biomechanics; underlying mechanisms and the functional consequences

Although approximately one-third of stroke survivors suffer abnormal foot posture and this can influence mobility [1], there is very little objective information regarding the foot and ankle after stroke

The effects of pronated foot posture and medial heel and forefoot wedge orthoses on static balance in older people

Aging has been associated with increasing foot pronation [1] and changes in foot mobility and posture which may influence standing balance [2, 3]. Orthotic interventions change foot posture [4] and load distribution under the foot [5] and therefore may have important effects on balance in older people

The effect of rollover footwear on pain, disability and lumbar posture in patients with low back pain

Low back pain (LBP) is one of the most common musculoskeletal disorders [1]. Exercise therapy is often advised [2, 3] but requires a significant time commitment, can rely on equipment or health professionals and risks low compliance. As an alternative or adjunct, shoes with a curved sole profile are thought to produce beneficial changes in ankle, knee, hip and back position and posture [4]. Therefore, the aim of this preliminary study was to investigate the effect of rollover footwear on pain, disability and lumbar posture in patients with lumbar pain

The effect of rollover footwear on head and trunk posture during standing

Footwear with a curved sole profile has become popular due to the proposed benefits to gait, posture and altered muscle activity and tone. In addition, rocker profiled footwear are one of the most commonly prescribed therapeutic shoes. The altered movement of the body over the foot due to the curved sole profile is assumed to alter the position of the hips and thereafter the trunk, spine and perhaps the head too. This could have some benefits for those with back pain [5]. However, whilst evidence for the effects on the lower limb is becoming comprehensive, there is a paucity of information for any effects on head and trunk posture

The effect of cognitive task on ankle movement variability in athletes with functional ankle instability

Gait has been generally viewed as a largely automated motor task, requiring minimal higher-level cognitive input. Increasing evidence, however, suggest that attention demanding cognitive tasks to disturb gait[1, 2]. Movement variability may influence joint stability and increase the risk of “giving way” at the ankle in individuals with functional ankle instability (FAI)[3]. The purpose of this study was to investigate the effect of dual-tasking on ankle movement variability in athletes with FAI

Effects of metatarsal domes on plantar pressures in older people with a history of forefoot pain

Background: Forefoot pads such as metatarsal domes are commonly used in clinical practice for the treatment of pressure-related forefoot pain, however evidence for their effects is inconsistent. This study aimed to evaluate the effects on plantar pressures of metatarsal domes in different positions relative to the metatarsal heads. Methods: Participants in this study included 36 community-dwelling adults aged 65 or older with a history of forefoot pain. Standardised footwear was used and plantar pressures were measured using the pedar®-X in-shoe plantar pressure measurement system. Peak pressure, maximum force and contact area were analysed using an anatomically-based masking protocol that included three forefoot mask sub-areas (proximal to, beneath, and distal to the metatarsal heads). Data were collected for two different types of prefabricated metatarsal domes of different densities (Emsold metatarsal dome and Langer PPT metatarsal pad) in three different positions relative to the metatarsal heads. Seven conditions were tested in this study: (i) control (no pad) condition, (ii) Emsold metatarsal dome positioned 5 mm proximal to the metatarsal heads, (iii) Emsold metatarsal dome positioned in-line with the metatarsal heads, (iv), Emsold metatarsal dome positioned 5 mm distal to the metatarsal heads, (v) Langer PPT metatarsal pad positioned 5 mm proximal to the metatarsal heads, (vi) Langer PPT metatarsal pad positioned in-line with the metatarsal heads, and (vii) Langer PPT metatarsal pad positioned 5 mm distal to the metatarsal heads. Results: When analysed with the mask that was distal to the metatarsal heads, where the plantar pressure readings were at their highest, all metatarsal dome conditions led to significant reductions in plantar pressure at the forefoot compared to the control (no pad) condition (F3.9, 135.6 = 8.125, p < 0.001). The reductions in plantar pressure were in the order of 45–60 kPa. Both the Emsold metatarsal dome and the Langer PPT metatarsal pad, when positioned proximal to the metatarsal heads, managed to achieve this without adversely increasing plantar pressure proximally where the pad was positioned, however the Emsold metatarsal dome was most effective. Conclusions: Metatarsal domes reduce plantar pressure in the forefoot in older people with a history of forefoot pain. All metatarsal dome conditions significantly reduced peak pressure in the forefoot, however metatarsal domes that were positioned 5 mm proximal to the metatarsal heads provided the best balance of reducing plantar pressure distal to the metatarsal heads, where the pressure is at its greatest, but not adversely increasing plantar pressure proximally, where the bulk of the pad is positioned. In this proximal position, the Emsold metatarsal dome was more effective than the Langer PPT metatarsal pad and we cautiously recommend this forefoot pad for alleviating forefoot pressure in older people with forefoot pain

Foot and ankle characteristics associated with fear of falling and mobility in community-dwelling older people: a cross-sectional study

Background Fear of falling is multifactorial in etiology and is associated with falls. It has been demonstrated that foot problems increase the risk of falls in older people. Therefore, the objective of this study was to investigate the associations of foot and ankle characteristics with fear of falling and mobility in community-dwelling older people. Method One hundred and eighty-seven community-dwelling older adults (106 females) aged 62–90 years (mean 70.5 ± 5.2) from Isfahan, Iran, were recruited. Foot and ankle characteristics (including foot posture, range of motion, muscle strength, deformity, tactile sensation, pain and dynamic function), fear of falling (Fall Efficacy Scale International) and mobility (Timed Up and Go Test) were measured. Two multivariate linear regression analyses identified variables independently associated with fear of falling and mobility. Results Linear regression analysis revealed that less ankle plantarflexor muscle strength, greater pressure-time integral, foot pain, and reduced tactile sensitivity of the ankle were significantly and independently associated with increased fear of falling. The total variance explained by the model was 59%. Less ankle plantarflexor muscle strength, greater pressure-time integral, and slower centre of pressure velocity were significantly and independently associated with poorer mobility. The total variance explained by the model was 48%. Conclusion Several foot and ankle characteristics are associated with fear of falling and mobility in older people. Targeting these modifiable risk factors may play a role in reducing fear of falling and enhancing mobility performance in this population

An anatomically-based masking protocol for the assessment of in-shoe plantar pressure measurement of the forefoot

Background The area beneath the metatarsal heads is a common location of foot pain, which is often associated with high plantar pressures. Current plantar pressure assessment protocols focus mainly on the gross area of the forefoot with minimal attention paid to specific areas such as the metatarsal heads. The aim of this study was to develop and assess a new anatomically-based masking protocol that is clinically relevant to measure forefoot plantar pressure during shod conditions based on the anatomical positions of the metatarsal heads. Methods Initially, we developed a masking protocol to measure forefoot plantar pressure during shod conditions based on the anatomical positions of the metatarsal heads. This new masking protocol divided the forefoot into three sub-areas (proximal, beneath, and distal to the metatarsal heads) as determined by the position of each metatarsal head. Following development of the new masking protocol, we compared the new protocol against a traditional protocol, which defines the forefoot as between 51 and 81% of the foot length. To compare the two masking protocols, we tested two experimental conditions: (i) a control condition (i.e. no metatarsal pad), and (ii) a metatarsal pad condition. We then compared plantar pressure differences between the two experimental conditions for the two masking protocols. Participants for this component of the study included 36 community dwelling older adults (mean age 75.6 years ±5.4) with a history of forefoot pain. Forefoot plantar pressure data were measured while walking using the pedar®-X in-shoe system. Peak pressure, maximum force and contact area at the time of peak pressure were determined and results were compared between the two masking protocols. Results The traditional masking protocol showed that the metatarsal pad significantly decreased peak pressure and increased contact area in the forefoot area (i.e. within the entire mask area), but maximum force was not significantly different between the two conditions. In contrast, the newly developed anatomically-based masking protocol indicated that the metatarsal pad decreased peak plantar pressures distal to and beneath the metatarsal heads by increasing force and contact area proximal to the metatarsal heads. Conclusions An anatomically-based masking protocol that is clinically relevant was developed to assess forefoot plantar pressure during shod conditions based on the anatomical positions of metatarsal heads. We propose that the new forefoot masking protocol will provide greater interpretability of forefoot plantar pressure data, which will aid clinicians and researchers for diagnostic, prognostic and therapeutic purposes