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Introduction: People with Parkinson's disease (PD) can be classified into tremor dominant (TD) and postural instability and gait difficulty (PIGD) subtypes; the latter group having more impaired gait and increased fall risk. While there is some evidence that anti-parkinsonian medication, levodopa, might not improve balance and gait control or reduce fall risk in the PIGD subtype, it is unclear whether the levodopa dosage intake affects gait stability. To address these issues, this study used accelerometry to compare gait stability: (i) during before and after levodopa intake between non-PIGD and PIGD subtypes; (ii) between individuals who took less or >750 mg of levodopa/day., Methods: In 15 non-PIGD (Combination of 13 TD patients and 2 classified as indeterminate subtype) and 23 PIGD participants of similar mean (SD) age ((63.0 (7.6) versus 62.6 (10.0) years, respectively)) and disease-duration (8.9 (8.9) versus 11.3 (4.6) years, respectively), head and trunk stability during gait was examined using anteroposterior, vertical and mediolateral acceleration harmonic ratios (HRs). Participants were assessed before and after a levodopa dose, during typical "off" and "on" periods, respectively., Results: Two-way analyses of variance (group × medication status) revealed that compared to the non-PIGD subgroup, the PIGD subgroup showed significantly worse head stability (lower anteroposterior HR) in the "off" state, and significantly worse pelvis stability (significantly lower mediolateral and vertical HRs) in the "on" state (p < 0.05 for both). Levodopa was effective in treating most of the disease-related impairments (not bradykinesia) in both groups, (p < 0.05) but improved gait stability (lowered pelvis mediolateral and vertical HRs) only in people with the non-PIGD subtype (p < 0.05) and those taking <750 mg of levodopa/day (p < 0.05)., Conclusions: People with the PD PIGD subtype exhibit impaired gait stability that is not improved and frequently worsened by levodopa. New non-pharmaceutical approaches, technological (e.g. cueing) or exercise-based (e.g. balance training) are required to improve or compensate for mediolateral gait instability in this subtype and ultimately prevent falls., (Copyright © 2018. Published by Elsevier Inc.)

Objective: The objective of this study was to compare centre of pressure characteristics during walking in individuals with and without first metatarsophalangeal joint osteoarthritis (1st MTPJ OA), in order to provide insights into alterations in foot function associated with this condition., Methods: Twenty people with 1st MTPJ OA and 20 asymptomatic controls matched for age, sex and body mass index underwent gait analysis using the emed ® -x400 plantar pressure system (Novel GmbH, Germany). Average and maximum centre of pressure velocity and lateral-medial force index during loading, midstance, terminal stance and preswing were compared between the groups., Results: During the preswing phase of gait, maximum centre of pressure velocity was significantly slower in individuals with 1st MTPJ OA (0.78 ± 0.19 vs 1.13 ± 0.36 m/sec; p = 0.003), and both average and maximum lateral-medial force indices were significantly higher in individuals with 1st MTPJ OA (0.98 ± 0.14 vs 0.82 ± 0.13; p < 0.001 and 1.37 ± 0.29 vs 1.15 ± 0.15; p = 0.008, respectively). Non-weightbearing 1st MTPJ dorsiflexion range of motion was significantly associated with maximum centre of pressure velocity (r = 0.54, p < 0.001) and average lateral-medial force index (r = -0.44, p = 0.004) during preswing., Conclusions: Individuals with 1st MTPJ OA exhibit significant differences in centre of pressure characteristics during propulsion, possibly due to decreased range of available 1st MTPJ dorsiflexion., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

Background: Foot posture is a risk factor for some lower limb injuries, however the underlying mechanism is not well understood. Plantar pressure analysis is one technique to investigate the interaction between foot posture and biomechanical function of the lower limb., Research Question: The aim of this review was to investigate the relationship between foot posture and plantar pressure during walking., Methods: A systematic database search was conducted using MEDLINE, CINAHL, SPORTDiscus and Embase to identify studies that have assessed the relationship between foot posture and plantar pressure during walking. Included studies were assessed for methodological quality. Meta-analysis was not conducted due to heterogeneity between studies. Inconsistencies included foot posture classification techniques, gait analysis protocols, selection of plantar pressure parameters and statistical analysis approaches., Results: Of the 4213 citations identified for title and abstract review, sixteen studies were included and underwent quality assessment; all were of moderate methodological quality. There was some evidence that planus feet display higher peak pressure, pressure-time integral, maximum force, force-time integral and contact area predominantly in the medial arch, central forefoot and hallux, while these variables are lower in the lateral and medial forefoot. In contrast, cavus feet display higher peak pressure and pressure-time integral in the heel and lateral forefoot, while pressure-time integral, maximum force, force-time integral and contact area are lower for the midfoot and hallux. Centre of pressure was more laterally deviated in cavus feet and more medially deviated in planus feet. Overall, effect sizes were moderate, but regression models could only explain a small amount of variance in plantar pressure variables., Significance: Despite these significant findings, future research would benefit from greater methodological rigour, particularly in relation to the use of valid foot posture measurement techniques, gait analysis protocols, and standardised approaches for analysis and reporting of plantar pressure variables., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Variations in foot posture, such as pes planus (low medial longitudinal arch) or pes cavus (high medial longitudinal arch) are associated with some lower limb injuries. However, the mechanism that links foot posture to injury is not clear. Research question The aim of this study was to compare plantar pressure between healthy individuals with normal, planus or cavus feet., Methods: Ninety-two healthy volunteers (aged 18 to 45) were classified as either normal (n = 35), pes planus (n = 31) or pes cavus (n = 26) based on the Foot Posture Index, Arch Index and normalised navicular height truncated. Barefoot walking trials were conducted using an emed ® -x400 plantar pressure system (Novel GmbH, Munich, Germany). An 11 region mask was used that included the medial heel, lateral heel, midfoot, 1st, 2nd, 3rd, 4th and 5th metatarsophalangeal joints, hallux, 2nd toe, and the 3rd, 4th and 5th toes. Peak pressure, pressure-time integral, maximum force, force-time integral and contact area were calculated for each region. One way analyses of variance and effect sizes were used to compare the three foot posture groups., Results: Overall, the largest differences were between the planus and cavus foot groups in forefoot pressure and force. In particular, peak pressures at the 4th and 5th MTPJs in the planus foot group were lower compared to the normal and cavus foot groups, and displayed the largest effect sizes. Significance This study confirms that foot posture does influence plantar pressures, and that each foot posture classification displays unique plantar pressure characteristics., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Footwear has the potential to influence balance in either a detrimental or beneficial manner, and is therefore an important consideration in relation to falls prevention. The objective of this study was to evaluate balance ability and gait patterns in older women while wearing prototype footwear and insoles designed to improve balance., Methods: Older women (n = 30) aged 65 - 83 years (mean 74.4, SD 5.6) performed a series of laboratory tests of balance ability (postural sway on a foam rubber mat, limits of stability and tandem walking, measured with the Neurocom® Balance Master) and gait patterns (walking speed, cadence, step length and step width at preferred speed, measured with the GAITRite® walkway) while wearing (i) flexible footwear (Dunlop Volley™), (ii) their own footwear, and (iii) prototype footwear and insoles designed to improve dynamic balance. Perceptions of the footwear were also documented using a structured questionnaire., Results: There was no difference in postural sway, limits of stability or gait patterns between the footwear conditions. However, when performing the tandem walking test, there was a significant reduction in step width and end sway when wearing the prototype footwear compared to both the flexible footwear and participants' own footwear. Participants perceived their own footwear to be more attractive, comfortable, well-fitted and easier to put on and off compared to the prototype footwear. Despite this, most participants (n = 18, 60%) reported that they would consider wearing the prototype footwear to reduce their risk of falling., Conclusion: The prototype footwear and insoles used in this study improve balance when performing a tandem walk test, as evidenced by a narrower step width and decreased sway at completion of the task. However, further development of the design is required to make the footwear acceptable to older women from the perspective of aesthetics and comfort., Trial Registration: Australian New Zealand Clinical Trials Registry. ACTRN12617001128381 , 01/08/2017 (retrospectively registered).

Background: Footwear worn indoors is generally less supportive than outdoor footwear and may increase the risk of falls., Objective: To evaluate balance ability and gait patterns in older women while wearing different styles of indoor footwear: a backless slipper and an enclosed slipper designed to optimise balance., Methods: Older women (n = 30) aged 65-83 years (mean 74.4, SD 5.6) performed a series of laboratory tests of balance ability (postural sway, limits of stability, and tandem walking, measured with the NeuroCom® Balance Master) and gait patterns (walking speed, cadence, and step length, measured with the GAITRite® walkway) while wearing (1) socks, (2) backless slippers with a soft sole, and (3) enclosed slippers with a firm sole and Velcro® fastening. Perceptions of the footwear were also documented using a structured questionnaire., Results: Significant overall effects of footwear were observed for postural sway, the limits of stability test (directional control), the tandem walk test (step width and end sway), and temporospatial gait patterns (walking speed, cadence, and step length). No footwear effects were observed for maximum excursion when performing the limits of stability test or for speed when performing the tandem walk test. Post hoc tests indicated that performances were best while wearing the enclosed slippers, intermediate with socks, and worst with backless slippers. The enclosed slippers were perceived to be more attractive, comfortable, and well fitted, but heavier than the backless slippers. Most participants (n = 23; 77%) reported that they would consider wearing the enclosed slippers to reduce their risk of falling., Conclusion: Indoor footwear with an enclosed heel, Velcro® fastening, and a firm sole optimises balance and gait compared to backless slippers, and is therefore recommended to reduce the risk of falling., (© 2016 The Author(s) Published by S. Karger AG, Basel.)

This systematic review evaluated the available evidence for the effects of Masai Barefoot Technology (MBT) footwear on lower limb biomechanics during gait. Electronic databases (MEDLINE, EMBASE, CINAHL, SPORTDiscus, and PubMed) were searched in January 2015. Methodological quality of included studies was evaluated using the Quality Index. Standardised mean differences and 95% confidence intervals were calculated, and meta-analysis was conducted where possible. 17 studies satisfied the inclusion criteria; 16 cross-sectional studies and one randomised control trial (RCT). Quality Index scores ranged from 7 to 12 (out of 15). All 17 studies investigated walking gait only. Evidence showed that MBT footwear caused asymptomatic individuals to walk with a shorter stride length, reduced peak hip flexion, increased peak knee extension, and reduced hip and knee range of motion throughout gait. All kinematic effects occurred in the sagittal plane. There was a trend towards a decrease in internal and external joint moments and power, except for the foot, where increases in force were observed. There were only a small number of changes to lower limb muscle amplitude and timing. No statistically significant effects were observed in symptomatic individuals with knee osteoarthritis or following total knee replacement, but there was an increase in cadence and a decrease in step length in individuals following tibiotalar arthrodesis. These findings suggest that MBT footwear does change lower limb biomechanics in both asymptomatic and symptomatic individuals during gait. However, further clinical trials need to be undertaken to determine whether these changes are therapeutically beneficial., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Variations in foot posture are associated with the development of some lower limb injuries. However, the mechanisms underlying this relationship are unclear. The objective of this study was to compare foot kinematics between normal, pes cavus and pes planus foot posture groups using a multi-segment foot model. Ninety-seven healthy adults, aged 18-47 were classified as either normal (n=37), pes cavus (n=30) or pes planus (n=30) based on normative data for the Foot Posture Index, Arch Index and normalised navicular height. A five segment foot model was used to measure tri-planar motion of the rearfoot, midfoot, medial forefoot, lateral forefoot and hallux during barefoot walking at a self-selected speed. Angle at heel contact, peak angle, time to peak angle and range of motion was measured for each segment. One way ANOVAs with post-hoc analyses of mean differences were used to compare foot posture groups. The pes cavus group demonstrated a distinctive pattern of motion compared to the normal and pes planus foot posture groups. Effect sizes of significant mean differences were large and comparable to similar studies. Three key differences in overall foot function were observed between the groups: (i) altered frontal and transverse plane angles of the rearfoot in the pes cavus foot; (ii) Less midfoot motion in the pes cavus foot during initial contact and midstance; and (iii) reduced midfoot frontal plane ROM in the pes planus foot during pre-swing. These findings indicate that foot posture does influence motion of the foot., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Good lateral harmonic stability in gait may be important for minimising fall risk in older people because many falls occur during walking when the base of support is narrowest in the mediolateral (ML) direction. However, the traditional ML harmonic ratio (MLHR) may be a sub-optimal measure of gait quality because of insufficient frequency resolution., Objective: The primary objective was to investigate if a new measure of lateral harmonic stability, the 8-step MLHR, could discriminate older fallers from non-fallers while taking different walking speeds into account., Methods: Repeat walks over 20 m were completed by 96 older people (mean age 80, SD 4 years); 35 participants had a history of one or more falls in the past year. The traditional MLHR and the 8-step MLHR were obtained from an accelerometer attached to the sacrum., Results: Compared to the traditional MLHR, the 8-step MLHR demonstrated similar univariate ability to identify significant differences in fall risk based on age, walking speed and physiology (p ≤ 0.05). When differences in walking speed were taken into account, we observed that participants who walked both faster than average and had above-average lateral harmonic stability (by the 8-step MLHR) were 5.3 times less likely to be fallers than all other participants (relative risk: 0.19, 95% confidence interval: 0.06-0.57). For the traditional MLHR, however, no significant differences between the fallers and non-fallers were evident., Conclusions: The findings indicate that good lateral harmonic stability interacts with adequate gait speed and, when coincident, are associated with reduced fall risk in older people. Future research could examine whether interventions focusing on enhancing both gait speed and lateral stability can reduce fall risk and whether these combined gait measures can remotely predict deteriorating health using wearable technology., (© 2014 S. Karger AG, Basel.)

The aim of this study was to investigate the prevalence of abnormal knee biomechanical patterns in 40 patients with a modern TKA prosthesis, compared to 40 matched control participants when ascending and descending stairs. Fewer patients were able to ascend (65%) or descend stairs (53%) unassisted than controls (83%). Of the participants who could ascend and descend, cluster analysis classified most patients (up to 77%) as demonstrating a similar knee moment pattern as all controls. A small subgroup of patients who completed the tasks did so with distinctly abnormal biomechanics compared to other patients and controls. These findings suggest that recovery of normal stair climbing is possible. However, rehabilitation might be more effective if it were tailored to account for these differences between patients., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Plantar forefoot pain is common in older people and is related to increased peak pressures under the foot during gait. Variations in the hardness of the shoe sole may therefore influence both the magnitude of loading under the foot and the perceived comfort of the shoe in this population. The aim of this investigation was to determine the effect of varying shoe sole hardness on plantar pressures and comfort in older people with forefoot pain. In-shoe plantar pressures under the forefoot, midfoot and rearfoot were recorded from 35 older people (mean age 73.2, SD 4.5 years) with current or previous forefoot pain using the pedar-X(®) system. Participants walked at their normal comfortable speed along an 8m walkway in shoes with three different levels of sole hardness: soft (Shore A25), medium (Shore A40) and hard (Shore A58). Shoe comfort was measured on a 100mm visual analogue scale. There were statistically significant differences in peak pressure of between 5% and 23% across the forefoot, midfoot and rearfoot (p<0.01). The hard-soled shoe registered the highest peak pressures and the soft-soled shoe the lowest peak pressures. However, no differences in comfort scores across the three shoe conditions were observed. These findings demonstrate that as shoe sole hardness increases, plantar pressure increases, however this does not appear to have a significant effect on shoe comfort., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Humans are living longer but morbidity has also increased; threatening to create a serious global burden. Our approach is to monitor gait for early warning signs of morbidity. Here we present highlights from a series of experiments into gait as a potential biomarker for Parkinson's disease (PD), ageing and fall risk. Using body-worn accelerometers, we developed several novel camera-less methods to analyze head and pelvis movements while walking. Signal processing algorithms were developed to extract gait parameters that represented the principal components of vigor, head jerk, lateral harmonic stability, and oscillation range. The new gait parameters were compared to accidental falls, mental state and co-morbidities. We observed: 1) People with PD had significantly larger and uncontrolled anterioposterior (AP) oscillations of the head; 2) Older people walked with more lateral head jerk; and, 3) the combination of vigorous and harmonically stable gait was demonstrated by non-fallers. Our findings agree with research from other groups; changes in human gait reflect changes to well-being. We observed; different aspects of gait reflected different functional outcomes. The new gait parameters therefore may be complementary to existing methods and may have potential as biomarkers for specific disorders. However, further research is required to validate our observations, and establish clinical utility.

Background: Slips are a common cause of falls, and nonslip socks have been marketed to prevent slips in older people. However, few studies have investigated the biomechanical and clinical effects of walking in nonslip socks. This study aimed to examine gait parameters in older people walking on a slippery surface wearing nonslip socks compared with standard sock and barefoot conditions., Methods: Fifteen older people completed five trials of the fast-paced Timed Up and Go test while barefoot and while wearing standard socks and nonslip socks. Kinematic data (step length, heel horizontal velocity at heel strike, and foot-floor angle at heel strike) and clinical data (total Timed Up and Go test time, total number of steps, number of steps in turn, and observed slips, trips, or falls) were collected., Results: Performance on the Timed Up and Go test did not differ between the barefoot and nonslip sock conditions; however, participants walked more slowly and took shorter steps when wearing standard socks. Participants rated nonslip socks to feel less slippery than barefoot and standard socks., Conclusions: Compared with wearing standard socks, wearing nonslip socks improves gait performance and may be beneficial in reducing the risk of slipping in older people.

Variations in foot posture, such as pes planus (low-arched foot) or pes cavus (high-arched foot), are thought to be an intrinsic risk factor for injury due to altered motion of the lower extremity. Hence, the aim of this systematic review was to investigate the relationship between foot posture and lower limb kinematics during walking. A systematic database search of MEDLINE, CINAHL, SPORTDiscus, Embase and Inspec was undertaken in March 2012. Two independent reviewers applied predetermined inclusion criteria to selected articles for review and selected articles were assessed for quality. Articles were then grouped into two broad categories: (i) those comparing mean kinematic parameters between different foot postures, and (ii) those examining associations between foot posture and kinematics using correlation analysis. A final selection of 12 articles was reviewed. Meta-analysis was not conducted due to heterogeneity between studies. Selected articles primarily focused on comparing planus and normal foot postures. Five articles compared kinematic parameters between different foot postures - there was some evidence for increased motion in planus feet, but this was limited by small effect sizes. Seven articles investigated associations between foot posture and kinematics - there was evidence that increasing planus foot posture was positively associated with increased frontal plane motion of the rearfoot. The body of literature provides some evidence of a relationship between pes planus and increased lower limb motion during gait, however this was not conclusive due to heterogeneity between studies and small effect sizes., (Copyright © 2013 Elsevier B.V. All rights reserved.)

We investigated the biomechanical changes that occur in the lower limb following total knee arthroplasty (TKA). Lower limb joint kinematics and kinetics were evaluated in 32 patients before and 12 months following TKA and 28 age-matched controls. Analysis of variance with Bonferroni-adjusted post-hoc tests showed no significant changes in knee joint kinematics and kinetics following TKA despite significant improvements in pain and function. Significant increases in peak ankle plantarflexion and dorsiflexion moments and ankle power generation were observed which may be a compensatory response to impaired knee function to allow sufficient power generation for propulsion. Differences in knee gait parameters may arise as a result of the presence of osteoarthritis and mechanical changes associated with TKA as well as retention of the pre-surgery gait pattern., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Excessive rearfoot eversion is thought to be a risk factor for patellofemoral pain syndrome development, based on theoretical rationale linking it to greater tibial internal rotation and hip adduction. This study aimed to establish the relationship of rearfoot eversion with tibial internal rotation and hip adduction during walking in individuals with and without patellofemoral pain syndrome., Methods: Twenty-six individuals with patellofemoral pain syndrome and 20 controls (18-35years) participated. Each underwent instrumented three-dimensional motion analysis during over-ground walking. Pearson's correlation coefficients (r) were calculated to establish the relationship of rearfoot eversion with tibial internal rotation and hip adduction (peak and range of motion)., Findings: Greater peak rearfoot eversion was associated with greater peak tibial internal rotation in the patellofemoral pain syndrome group (r=0.394, P=0.046). Greater rearfoot eversion range of motion was associated with greater hip adduction range of motion in the patellofemoral pain syndrome (r=0.573, P=0.002) and control (r=0.460, P=0.041) groups; and greater peak hip adduction in the control group (r=0.477, P=0.033)., Interpretation: Associations between greater rearfoot eversion and greater hip adduction indicate that interventions targeted at the foot or hip in individuals with patellofemoral pain syndrome may have similar overall effects on lower limb motion and clinical outcomes. The relationship between rearfoot eversion and tibial internal rotation identified in the patellofemoral pain syndrome group may be related to aetiology. However, additional prospective research is needed to confirm this., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

An abnormal flexor moment pattern is often evident following total knee replacement (TKR) surgery. We investigated whether such a pattern at 12 months post-surgery could be predicted using biomechanical gait measures assessed before surgery and at 4 months post-surgery. Thirty two TKR patients were evaluated and classified as normal (biphasic pattern) or abnormal (flexor moment pattern) at each time point. Biomechanical parameters collected before surgery and at 4 months post-surgery were then explored for their ability to predict gait patterns at 12 months post-surgery. The gait pattern at 4 months was significantly associated with the 12 month post-surgery gait pattern, with over half of those with a flexor moment pattern at 4 months retaining this pattern at 12 months. Discriminant function analysis indicated that peak knee flexion during early stance, peak knee extension, and peak knee extension moment at 4 months post-surgery were independent predictors of the gait pattern at 12 months. Thus, an abnormal knee flexor moment pattern at 12 months post-surgery can be predicted by biomechanical analysis 4 months after surgery. Therefore, interventions aimed at improving active extension may need to be implemented early after surgery to restore a normal gait pattern., (Copyright © 2011 Orthopaedic Research Society.)

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., (Copyright © 2011 Elsevier B.V. All rights reserved.)

People who have undergone total knee replacement (TKR) experience difficulties in some daily activities including walking. Walking at faster speeds requires more knee flexion and may therefore present a greater challenge following TKR. The aim of this study was to compare the knee kinematics of patients following TKR and unimpaired controls during comfortable and fast walking speeds. Forty patients (22 women, 18 men) 12 months following TKR and 40 control participants (matched for age and sex) were assessed during walking at self-selected comfortable and fast speeds using three dimensional motion analysis. The group averages of spatiotemporal and peak kinematic characteristics in the sagittal, coronal and transverse movement planes were compared using univariate analysis of variance with walking speed as a co-variate. The TKR group walked with significantly reduced cadence (p < 0.001 at both speeds) and reduced stride length (p < 0.001 at both speeds), less knee flexion during stance and swing phases (p < 0.001 for both speeds) and less knee extension during stance phase (p < 0.024 for comfortable speed; p < 0.042 for fast speed). The TKR group also walked with less peak knee external rotation than controls at both speeds (p < 0.001 for both speeds). Both groups increased their velocity, cadence and stride length by a similar proportion when walking at fast speed. When walking at a faster speed, spatiotemporal gait parameters and knee motion are altered in a similar manner for both TKR patients and controls. However, at both walking speeds, TKR patients exhibit residual deficits 12 months following surgery., (Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.)

Foot posture is thought to influence predisposition to overuse injuries of the lower limb. Although the mechanisms underlying this proposed relationship are unclear, it is thought that altered foot kinematics may play a role. Therefore, this study was designed to investigate differences in foot motion between people with normal- and flat-arched feet using the Oxford Foot Model (OFM). Foot posture in 19 participants was documented as normal-arched (n=10) or flat-arched (n=9) using a foot screening protocol incorporating measurements from weightbearing antero-posterior and lateral foot radiographs. Differences between the groups in triplanar motion of the tibia, rearfoot and forefoot during walking were evaluated using a three-dimensional motion analysis system incorporating a multi-segment foot model (OFM). Participants with flat-arched feet demonstrated greater peak forefoot plantar-flexion (-13.7° ± 5.6° vs -6.5° ± 3.7°; p=0.004), forefoot abduction (-12.9° ± 6.9° vs -1.8° ± 6.3°; p=0.002), and rearfoot internal rotation (10.6° ± 7.5° vs -0.2°± 9.9°; p=0.018) compared to those with normal-arched feet. Additionally, participants with flat-arched feet demonstrated decreased peak forefoot adduction (-7.0° ± 9.2° vs 5.6° ± 7.3°; p=0.004) and a trend towards increased rearfoot eversion (-5.8° ± 4.4° vs -2.5° ± 2.6°; p=0.06). These findings support the notion that flat-arched feet have altered motion associated with greater pronation during gait; factors that may increase the risk of overuse injury., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Background: One of the hypothesised mechanisms by which foot orthoses obtain their clinical effect is by influencing muscle activity, however previous studies have reported highly variable findings. The aim of this study was to determine whether orthoses change muscle activity in people with flat-arched feet towards a pattern observed in people with normal-arched feet., Methods: Thirty young asymptomatic adults with flat-arched feet were recruited. Foot posture was classified using two clinical measurements and four skeletal alignment measurements from weight-bearing foot x-rays. Electromyographic activity was recorded while walking from tibialis posterior and peroneus longus via in-dwelling wire electrodes, and from tibialis anterior and medial gastrocnemius via surface electrodes. Four experimental conditions were assessed: (i) barefoot, (ii) shoe only, (iii) a heat-moulded (modified) prefabricated foot orthosis, and (iv) a 20-degree inverted-style customised foot orthosis., Findings: During the contact phase of gait, tibialis posterior electromyographic amplitude decreased significantly with the prefabricated orthosis (peak amplitude - 19% decrease, P=0.007; RMS amplitude--22% decrease, P=0.002) and the customised orthosis (peak amplitude--12% decrease, P<0.001, RMS amplitude--13% decrease, P=0.001), compared with the shoe-only condition. During the midstance/propulsive phase, peroneus longus electromyographic amplitude increased significantly with the prefabricated orthosis, compared with the shoe-only (peak amplitude--21% increase, P=0.024; RMS amplitude--24% increase, P=0.019) and customised orthosis conditions (peak amplitude--16% increase, P=0.028)., Interpretation: The foot orthoses significantly altered tibialis posterior and peroneus longus electromyographic amplitude. However, only the modified prefabricated orthosis changed peroneus longus electromyographic amplitude towards a pattern observed with normal-arched feet. Otherwise, few differences were found between the modified prefabricated and customised orthoses. Further research is required to determine whether these changes in muscle function are associated with clinical outcomes., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

The purpose of this study was to determine the reliability of investigating electromyography (EMG) of selected leg muscles during walking. Tibialis posterior and peroneus longus EMG activity were recorded via intramuscular electrodes. Tibialis anterior and medial gastrocnemius EMG activity were recorded with surface electrodes. Twenty-eight young adults attended two test-sessions approximately 15 days apart. Relative and absolute measures of reliability were calculated for EMG timing and amplitude parameters during specific phases of the gait cycle. Maximum contractions and sub-maximal contractions were obtained via maximum isometric voluntary contractions and a very fast walking speed, respectively. Time of peak EMG amplitude for all muscles displayed relatively narrow limits of random error. However, reliability of peak and root mean square amplitude parameters for tibialis posterior and peroneus longus displayed unacceptably wide limits of random error, regardless of the normalisation reference technique. Whilst some amplitude parameters for tibialis anterior and medial gastrocnemius displayed good to excellent relative reliability, the corresponding values for absolute error were generally large. Timing and amplitude EMG parameters for all muscles displayed low to moderate coefficient of variation within each test session (range: 7-25%). Overall, between-participant variability was minimised with sub-maximal normalisation values. These results demonstrate that re-application of electrodes results in large random error between sessions, particularly with tibialis posterior and peroneus longus. Researchers planning studies of these muscles with a repeated-test design (e.g. to evaluate the effect of an intervention) must consider whether this level of error is acceptable., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Development of patellofemoral pain syndrome (PFPS) is considered to be multifactorial. The aims of this systematic review were to (i) summarise and critique the body of literature addressing kinematic gait characteristics associated with PFPS; and (ii) provide recommendations for future research addressing kinematic gait characteristics associated with PFPS. A comprehensive search of MEDLINE, EMBASE, CINAHL, and Current Contents revealed 561 citations for review. Each citation was assessed for inclusion and quality using a modified version of the 'Quality Index' and a novel inclusion/exclusion criteria checklist by two independent reviewers. A total of 24 studies were identified. No prospective studies with adequate data to complete effect size calculations were found. Quality of included case-control studies varied, with a number of methodological issues identified. Heterogeneity between studies made meta-analysis inappropriate. Reductions in gait velocity were indicated during walking, ramp negotiation, and stair negotiation in individuals with PFPS. Findings indicated delayed timing of peak rearfoot eversion and increased rearfoot eversion at heel strike transient during walking; and delayed timing of peak rearfoot eversion, increased rearfoot eversion at heel strike, reduced rearfoot eversion range, greater knee external rotation at peak knee extension moment, and greater hip adduction during running in individuals with PFPS. There is a clear need for prospective evaluation of kinematic gait characteristics in a PFPS population to distinguish between cause and effect. Where possible, future PFPS case-control studies should consider evaluating kinematics of the knee, hip and foot/ankle simultaneously with larger participant numbers. Completing between sex comparisons when practical and considering spatiotemporal gait characteristics during methodological design and data analysis is also recommended.

The aim of this study was to systematically investigate the influence of various walking surfaces and footwear characteristics on the ability to terminate gait rapidly in 10 young and 26 older people. Subjects walked at a self-selected speed in eight randomized shoe conditions (standard versus elevated heel, soft sole, hard sole, high-collar, flared sole, bevelled heel and tread sole) on three surfaces: control, irregular and wet. In response to an audible cue, subjects were required to stop as quickly as possible in three out of eight walking trials in each condition. Time to last foot contact, total stopping time, stopping distance, number of steps to stop, step length and step width post-cue and base of support length at total stop were calculated from kinematic data collected using two CODA scanner units. The older subjects took more time and a longer distance to last foot contact and were more frequently classified as using a three or more-steps stopping strategy compared to the young subjects. The wet surface impeded gait termination, as indicated by greater total stopping time and stopping distance. Subjects required more time to terminate gait in the soft sole shoes compared to the standard shoes. In contrast, the high-collar shoes reduced total stopping time on the wet surface. These findings suggest that older adults have more difficulty terminating gait rapidly than their younger counterparts and that footwear is likely to influence whole-body stability during challenging postural tasks on wet surfaces.

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 reliability of measures of walking in people with Alzheimer's disease (AD) has not been established despite the increased variability of their walking compared to control groups. The purpose of this study was to examine the test-retest reliability of temporal and spatial gait measurements in community dwelling people with AD. Ten males and 10 females with AD completed 10 walks on an instrumented walkway at self-selected comfortable speed on two occasions, 1 week apart. Data from 10 walks for each subject for each session were averaged and test-retest reliability of velocity, cadence, step length, stride length, step width, toe in/out angle, swing and stance times was measured using intraclass correlation coefficients (ICCs) of the type (3, 1). Coefficients of variation (CV) of method error were calculated to determine between-trial variability and the minimum detectable change (MDC) was calculated to indicate the difference in scores required to show a true change. This analysis was repeated for averages of the first three walks for each subject at each session. ICCs were found to be high (>0.86) for all gait parameters using both 10 and three walks, indicating high test-retest reliability for these measures in people with AD with as few as three walks. Measures of support base and toe in/out angle, however, had higher CV, even with increased numbers of walks, suggesting that only large changes in these parameters can be detected. MDC values suggested that demonstration of real change in gait measures is feasible in this population.

The popularity of using accelerometer-based systems to quantify human movement patterns has increased in recent years for clinicians and researchers alike. The benefits of using accelerometers compared to more traditional gait analysis instruments include low cost; testing is not restricted to a laboratory environment; accelerometers are small, therefore walking is relatively unrestricted; and direct measurement of 3D accelerations eliminate errors associated with differentiating displacement and velocity data. However, accelerometry is not without its disadvantages, an issue which is scarcely reported in gait analysis literature. This paper reviews the use of accelerometer technology to investigate gait-related movement patterns, and addresses issues of acceleration measurement important for experimental design. An overview of accelerometer mechanics is provided before illustrating specific experimental conditions necessary to ensure the accuracy of gait-related acceleration measurement. A literature review is presented on how accelerometry has been used to examine basic temporospatial gait parameters, shock attenuation, and segmental accelerations of the body during walking. The output of accelerometers attached to the upper body has provided useful insights into the motor control of normal walking, age-related differences in dynamic postural control, and gait patterns in people with movement disorders.

Background/aims: Variability of constant speed walking is closely related to falls risk in people with Alzheimer's disease (AD) who fall at 3 times the rate of normal elders. Falls are likely to be provoked during gait initiation, so this study aimed to determine if people with mild-moderate AD have greater variability of gait at initiation., Methods: Measures of step and stride length and time, step width and double support time were recorded during gait initiation for 10 males and 10 females with AD and 20 age- and gender-matched controls. Variability was calculated using the coefficient of variation (CV). Effect size was calculated using Cohen's d., Results: During gait initiation AD participants had greater variability than controls in stride timing (AD CV = 4.65, Control CV = 3.64; p < 0.05, d = 0.71) and double support proportion (AD CV = 9.40, Control CV = 7.62; p < 0.05, d = 0.8)., Conclusion: Increased timing variability in people with AD occurs during gait initiation as well as during constant speed walking and is evident in the early disease stages., (Copyright 2008 S. Karger AG, Basel.)

The aim of this study was to evaluate the hypothesis that an individual's preferred or usual walking speed, step length and cadence optimize the stability of head and pelvic accelerations in vertical (V), anterior-posterior (AP) and medio-lateral (ML) planes when walking. Acceleration patterns of the head and pelvis were recorded in ten healthy young adults as they walked on a level surface in three separate experiments: (1) walking at five different speeds, ranging from very slow to very fast; (2) walking in time to a metronome set at five different cadences, ranging from 33 to 167% of subjects' usual cadence; and (3) walking at five different step lengths varying from very short to very long while keeping in time with a metronome set at cadences 67, 100 and 125% of usual cadence. The results indicated that acceleration patterns in the V and AP planes were most stable when subjects walked at their usual cadence and step length. In the ML plane, stability was suboptimal, but still adequate, with the usual cadence and step length. The findings suggest that healthy young people walk in a manner that maximizes V and AP stability while maintaining adequate, though suboptimal ML stability.

Many falls in older people occur while walking, however the mechanisms responsible for gait instability are poorly understood. Therefore, the aim of this study was to develop a plausible model describing the relationships between impaired sensorimotor function, fear of falling and gait patterns in older people. Temporo-spatial gait parameters and acceleration patterns of the head and pelvis were obtained from 100 community-dwelling older people aged between 75 and 93 years while walking on an irregular walkway. A theoretical model was developed to explain the relationships between these variables, assuming that head stability is a primary output of the postural control system when walking. This model was then tested using structural equation modeling, a statistical technique which enables the testing of a set of regression equations simultaneously. The structural equation model indicated that: (i) reduced step length has a significant direct and indirect association with reduced head stability; (ii) impaired sensorimotor function is significantly associated with reduced head stability, but this effect is largely indirect, mediated by reduced step length, and; (iii) fear of falling is significantly associated with reduced step length, but has little direct influence on head stability. These findings provide useful insights into the possible mechanisms underlying gait characteristics and risk of falling in older people. Particularly important is the indication that fear-related step length shortening may be maladaptive.

Background: Hallux valgus is a common condition that may lead to considerable pain and disability. There is also evidence that hallux valgus may impair balance and increase the risk of falling in older people. Although a number of plantar pressure studies have been undertaken in people with and without hallux valgus, little is known about how hallux valgus affects basic gait patterns or the movement of the upper body when walking., Methods: Measurements of temporospatial parameters of gait and acceleration patterns of the head and pelvis were obtained in 71 people (24 men, 47 women) between 75 and 93 (mean 80 +/- 4) years of age when walking on both a level surface and a specially designed irregular walkway. Foot problems, vision, peripheral sensation, strength, and reaction time also were evaluated., Results: After adjusting for potential confounders, subjects with moderate to severe hallux valgus were found to exhibit significantly reduced velocity and step length on both walking surfaces and less rhythmic acceleration patterns in the vertical plane when walking on the irregular surface compared to subjects with no or mild hallux valgus., Conclusion: These findings indicate that hallux valgus has a significant detrimental impact on gait patterns that may contribute to instability and risk of falling in older people, particularly when walking on irregular terrain.

Pressures under the foot during level walking were measured in 15 healthy young adults (8 females, 7 males, mean age 25.7, S.D. 5.3) before and after immersing the feet in ice-cold water (2 degrees C) for 30 min to evaluate the role of plantar insensitivity on gait patterns. Following ice water immersion, there was a significant decrease in walking speed. Maximum forces and peak pressures under the foot decreased, with the exception of an increase in loading under the third to fifth metatarsal heads. Contact times increased under all regions of the foot, and force-time and pressure-time integrals increased under the second and third to fifth metatarsal head regions. It is concluded that plantar insensitivity significantly alters the distribution, duration, and to a lesser extent, the magnitude of forces and pressures under the foot when walking. These results suggest that in the neuropathic foot, gait changes caused by plantar insensitivity may be partly responsible for the redistribution and altered duration of loading, whereas the increase in the magnitude of forces and pressures are primarily due to other disease-related factors.

The purpose of this study was to evaluate the test-retest reliability of an instrumented walkway system (the GAITRite mat) for the measurement of temporal and spatial parameters of gait in young and older people. Thirty young subjects (12 males, 18 females) aged between 22 and 40 years (mean 28.5, S.D. 4.8) and 31 older subjects (13 males, 18 females) aged between 76 and 87 years (mean 80.8, S.D. 3.1) walked at a self-selected comfortable walking speed across the pressure-sensor mat three times and repeated the process approximately 2 weeks later. Intra-class correlation coefficients (ICC), coefficients of variation (CV) and 95% limits of agreement were then determined. For both groups of subjects, the reliability of walking speed, cadence and step length was excellent (ICCs between 0.82 and 0.92 and CVs between 1.4 and 3.5%). Base of support and toe in/out angles, although exhibiting high ICCs, were associated with higher CVs (8.3-17.7% in young subjects and 14.3-33.0% in older subjects). It is concluded that the GAITRite mat exhibits excellent reliability for most temporo-spatial gait parameters in both young and older subjects, however, base of support and toe in/out angles need to viewed with some caution, particularly in older people., (Copyright 2003 Elsevier B.V.)

The aim of this study was to evaluate acceleration patterns at the head and pelvis while subjects walked on a level and an irregular walking surface, to develop an understanding of how the postural control system responds to challenging walking conditions. Thirty young, healthy subjects walked on a level corridor and on artificial grass underlain with foam and wooden blocks placed in an arbitrary manner. Temporo-spatial gait parameters and acceleration patterns at the head and pelvis were measured. The results revealed that when walking on the irregular surface, subjects were able to maintain their velocity, but adopted a slower and more variable cadence and a significantly longer stride length. The magnitude of pelvis accelerations increased, however head accelerations were not affected by the walking surface. When considered as an overall pattern of movement, these findings suggest that one of the primary objectives of the postural control system when walking on irregular surfaces is head control, and that subjects adapt their stepping pattern on irregular surfaces to ensure that the head remains stable.

Background: Heel lifts, placed inside footwear are recommended for the management of numerous musculoskeletal conditions. Despite the potential therapeutic benefit of heel lifts, the mechanism(s) by which they exert their effects is unclear. The aim of this systematic review was to synthesise reported findings and summarise the effects of heel lifts on lower limb biomechanics and muscle function.Research Question: Do heel lifts affect lower limb biomechanics and muscle function during walking and running?Methods: Electronic databases (MEDLINE, EMBASE, CINAHL, SPORTDiscus, AMED) were searched from inception to April 2018. Studies were included if they (i) included participants without a limb length discrepancy or neurological condition, (ii) evaluated the effect of bilateral heel lifts that were removable (attached to the participants' foot (barefoot) or inserted inside footwear) or an existing feature of a shoe, and (iii) assessed lower limb biomechanics or muscle function during walking or running in asymptomatic or symptomatic participants.Results: A total of 23 studies (377 participants) were included. Study quality, assessed using a Modified Quality Index, ranged from 5 to 13 out of 15. A large number of biomechanical parameters were assessed, but few effects were statistically significant. The differences that were significant and had a large effect size are described below. In asymptomatic participants, heel lifts of 10 mm decreased duration of swing phase (standardised mean difference [SMD] = -1.3) and heel lifts of at least 5 cm decreased velocity (SMD = -0.93) during walking. In asymptomatic participants, heel lifts of 15 mm decreased maximum ankle dorsiflexion angle (SMD = -1.5) and heel lifts of 12 and 18 mm decreased gastrocnemius muscle tendon unit length (SMD = -0.96) during running. In participants with restricted ankle joint dorsiflexion, heel lifts of 6 and 9 mm increased medial gastrocnemius electromyography amplitude (SMD between 0.68 and 0.98) during walking. In participants with haemophilia, heel lifts of 9 mm increased ankle joint maximum range of motion (SMD = 1.6) during walking.Significance: Heel lifts affect specific lower limb biomechanical and muscle function parameters during walking and running. The clinical relevance and potential therapeutic benefits of these effects needs further investigation. [ABSTRACT FROM AUTHOR]

Highlights: [•] This is the first study to investigate the effect of walking speed on tibialis posterior EMG. [•] Walking speed strongly influenced muscle EMG amplitude in the lower leg. [•] Temporal EMG changes were muscle and phase specific. [•] TP, PL and MG peak EMG were similar at very slow to normal speeds. [ABSTRACT FROM AUTHOR]

Background Plantar forefoot pain is commonly experienced by older people and it is often treated with forefoot pads to offload the painful area. However, studies have found inconsistent effects for different forefoot pads on plantar pressure reduction, and optimum forefoot pad placement is still not clear. The aim of this study was to compare the effects of different forefoot pads on plantar pressure under the forefoot in older people with forefoot pain. Methods Thirty-seven adults (31 females, 6 males) with a mean age of 73.5 (SD 4.8) participated. Forefoot plantar pressure data were recorded using the pedar®-X in-shoe system while participants walked along an 8 m walkway. Five conditions were tested in a standardised shoe: (i) no padding (the control); (ii) a metatarsal dome positioned 10 mm proximal to the metatarsal heads, (iii) a metatarsal dome positioned 5 mm distal to the metatarsal heads, (iv) a metatarsal bar, and (v) a plantar cover. Results Compared to the shoe-only control condition, each of the forefoot pads significantly reduced forefoot peak pressure and maximum force. The metatarsal dome positioned 5 mm distal to the metatarsal heads and the plantar cover were most effective for reducing peak pressure (17%, p < 0.001 and 19%, p < 0.001, respectively). Conclusions These findings indicate that forefoot pads are effective for reducing forefoot pressures in older people with forefoot pain, and that the position of the pad relative to the metatarsal heads may be more important than the shape of the pad. [ABSTRACT FROM AUTHOR]

Objective. Abnormal foot posture and function have been proposed as possible risk factors for low back pain, but this has not been examined in detail. The objective of this study was to explore the associations of foot posture and foot function with low back pain in 1930 members of the Framingham Study (2002–05).Methods. Low back pain, aching or stiffness on most days was documented on a body chart. Foot posture was categorized as normal, planus or cavus using static weight-bearing measurements of the arch index. Foot function was categorized as normal, pronated or supinated using the centre of pressure excursion index derived from dynamic foot pressure measurements. Sex-specific multivariate logistic regression models were used to examine the associations of foot posture, foot function and asymmetry with low back pain, adjusting for confounding variables.Results. Foot posture showed no association with low back pain. However, pronated foot function was associated with low back pain in women [odds ratio (OR) = 1.51, 95% CI 1.1, 2.07, P = 0.011] and this remained significant after adjusting for age, weight, smoking and depressive symptoms (OR = 1.48, 95% CI 1.07, 2.05, P = 0.018).Conclusion. These findings suggest that pronated foot function may contribute to low back symptoms in women. Interventions that modify foot function, such as orthoses, may therefore have a role in the prevention and treatment of low back pain. [ABSTRACT FROM PUBLISHER]

Background. Falls are common in older people with Parkinson's disease (PD) and are likely to be related to gait disturbances associated with the condition. Although several studies have evaluated differences in basic gait parameters in people with PD, none have directly evaluated the stability of the upper body during gait. Methods. Temporospatial gait parameters and acceleration patterns at the head and pelvis were measured in three groups of older people: 33 controls without PD (mean age 67 ± 4 years), 33 older people with PD and no history of falls (mean age 63 ± 4 years), and 33 older people with PD and a history of falls (mean age 67 ± 2 years). Harmonic ratios of head and pelvis accelerations in each plane were calculated to provide an indicator of upper body stability. Results. Compared with the control group, older people with PD exhibited significantly reduced walking speed and step length and increased step timing variability. Acceleration patterns were also significantly less rhythmic at the head and pelvis in all three planes. After adjusting for differences in walking speed' and step timing variability, PD fallers exhibited significantly less rhythmic accelerations at the pelvis in the vertical and anteroposterior planes than PD nonfallers. Conclusions. Acceleration patterns during gait differ between older people with and without PD and between older people with PD who do and do not fall. These findings suggest that an inability to control displacements of the torso when walking may predispose older people with PD to falls. [ABSTRACT FROM AUTHOR]

Abstract: Menant JC, Perry SD, Steele JR, Menz HB, Munro BJ, Lord SR. 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. [Copyright &y& Elsevier]

Abstract: The aim of this study was to compare foot characteristics and plantar force and pressure patterns in young and older people. Fifty young (mean age 20.9±2.6 years) and 50 older (mean age 80.2±5.7 years) people without foot problems underwent tests of foot posture, range of motion, strength, sensation and deformity. Plantar force and pressure distribution during gait were evaluated using a floor-mounted resistive sensor mat system. Older participants exhibited flatter/more pronated feet, reduced range of motion of the ankle and 1st metatarsophalangeal joints, a higher prevalence of hallux valgus, toe deformities and toe plantarflexor weakness, and reduced plantar tactile sensitivity. Plantar pressure analysis revealed decreased magnitude of forces and pressures under the heel (−13% to 16%), metatarsophalangeal joints (−11% to 16%) and hallux (−19% to 25%), but greater relative contact time under the heel (+21%), midfoot (+14%) and metatarsophalangeal joints (+5% to 8%) in older participants. Multiple regression analysis revealed that these age-related differences could be largely explained by differences in step length and various foot characteristics, particularly foot posture and the severity of hallux valgus. These findings indicate that ageing is associated with significant changes in foot characteristics which contribute to altered plantar loading patterns during gait. [Copyright &y& Elsevier]

Abstract: The aim of this study was to determine the extent to which clinical tests of structural characteristics of the foot and ankle could account for variation in the magnitude of regional forces and pressures under the foot during walking in older people. Plantar forces and pressures were obtained from 172 older people (53 men, 119 women) aged 62–96 years (mean 80.0, S.D. 6.4) using a floor-mounted resistive sensor mat system. Subjects also completed tests of foot posture, range of motion, strength, sensation and toe deformity. Multiple regression analysis was then used to determine which clinical variables were most strongly correlated with plantar forces and pressures. Maximum forces and peak pressures under most regions of the foot were largely explained by differences in bodyweight, with some important exceptions. Loading under the midfoot was associated with the arch index, loading under the first metatarsophalangeal joint (1st MPJ) was associated with 1st MPJ range of motion, and loading under the hallux was associated with hallux plantarflexor strength, 1st MPJ range of motion and the degree of hallux valgus deformity. Clinical measurements accounted for 13–53% of the variance in maximum force and 4–40% of the variance in peak pressures. These findings indicate that structural foot and ankle characteristics identified from clinical measurements can explain some key aspects of plantar loading patterns of the foot. This information provides further insights into the dynamic function of the foot, which might assist in the development of interventions for pressure-related foot complaints in older people. [Copyright &y& Elsevier]

Midfoot osteoarthritis (OA) is a common condition, however its aetiology is not well understood. Understanding how plantar pressures differ between people with and without midfoot OA may provide insight into the aetiology and how best to manage this condition. To compare plantar pressures between people with and without symptomatic radiographic midfoot OA. This was a cross-sectional study of adults aged ≥ 50 years registered with four UK general practices who reported foot pain in the past year. Symptomatic radiographic midfoot OA was defined as midfoot pain in the last four weeks, combined with radiographic OA in one or more midfoot joints. Cases were matched 1:1 for sex and age (± 5 years) to controls. Peak plantar pressure and maximum force in 10 regions of the foot were determined using a pressure platform (RSscan International, Olen, Belgium) and compared between the groups using independent samples t -tests and effect sizes (Cohen's d). We included 61 midfoot OA cases (mean age 67.0, SD 8.1, 31 males, 30 females) and matched these to 61 controls (mean age 66.0, SD 7.9). Midfoot OA cases displayed greater force (d =0.79, medium effect size, p = <0.001) and pressure at the midfoot (d =0.70, me d ium effect size, p = <0.001), greater force at the fourth metatarsophalangeal (MTP) joint (d =0.28, small effect size, p = 0.13), and fifth MTP joint (d =0.37, small effect size, p = 0.10) and greater pressure at the fifth MTP joint (d =0.34, small effect size, p = 0.13). They also dis p layed lower force (d =0.40, small effect size, p = 0.02) and pressure at the hallux (d =0.50, medium effect size, p = <0.001) and lower force (d =0.54, medium effect size, p = <0.001) and pressure at the lesser toes (d =0.48, small effect size, p = <0.001) compare d with controls. Midfoot OA appears to be associated with lowering of the medial longitudinal arch, greater lateral push off and less propulsion at toe off. Longitudinal studies are needed to establish causal relationships. • People with midfoot OA displayed greater forces and pressures within the midfoot. • They had greater forces and pressures in the lateral forefoot and lower in the toes. • Midfoot OA appears associated with the lowering of the medial longitudinal arch. • It is also associated with greater lateral push off and less propulsion at toe off. • Future studies should assess interventions designed to normalise foot loading. [ABSTRACT FROM AUTHOR]

Repetitive impacts during running are associated with some running injuries. Tibial acceleration is a proxy for tibial loading, and interventions that can decrease it are likely to be of interest to the running community. What effect do running gait cues have on peak vertical tibial acceleration at a comfortable and moderate running pace, and how will these cues be executed? Twenty-seven participants ran on a treadmill according to the following cues in random order: run softly and lightly, run with shorter steps, and increase preferred step rate by 7.5 %. Participants maintained each condition for one minute before returning to their 'preferred' running pattern for two minutes. Two tibia-mounted inertial measurement unit sensors were used to collect tibial acceleration data at a 'comfortable' and 'moderate' run pace. A repeated measures analysis of variance test was used to compare the means between running conditions. Compared to preferred running, the decrease step length (−8 %, p = 0.002, Cohen's d =0.33) and run softly and lightly (−9 %, p = 0.040, Cohen's d =0.38) cues provided a significant reduction in peak vertical tibial acceleration during a comfortable run pace. No significant difference was observed with an increase in step rate. Compared to preferred running, there was no significant difference in peak vertical tibial acceleration with any of the running gait cues during a moderate run pace. Instructing runners to decrease step length or run softly and lightly can result in small reductions in peak vertical tibial acceleration during a comfortable run pace, but running gait cues during a moderate run pace provide no effects. Differences in the execution of each cue are likely to influence overall tibial loading throughout the stride cycle. These findings provide novel biomechanical evidence for the potential effects of running retraining strategies for reducing tibial accelerations at different running paces. • Running gait cues can be effective in reducing tibial loads at a comfortable pace. • Using gait cues to reduce tibial loads at a moderate pace is more of a challenge. • Cues to increase step rate and decrease step length do not provide the same effect. [ABSTRACT FROM AUTHOR]

Abstract: Longitudinal gait measures may be used to provide baseline data for intervention studies. This has not previously been reported in people with Alzheimer''s Disease. In this study measures of walking and their variability were recorded for 19 people with Alzheimer''s Disease on two occasions 1 year apart. Matched controls were measured once. Variability was calculated using the coefficient of variation (CV). Effect size was calculated using Cohen''s d. Gait was slower and more variable in the Alzheimer''s Disease group compared to controls. Over 1 year there was a decrease in velocity (initial=103.9cm/s, follow-up=95.1cm/s; p <0.05, d =0.4) and stride length (initial=119.6cm, follow-up=112.5cm; p <0.05, d =0.34) and an increase in double support (initial=24.2%, follow-up=30.1%; p <0.05, d =0.99) and stride length variability (initial CV=3.5%, follow-up CV=4.6%; p <0.05, d =0.65). These changes occurred in mild as well as more severe Alzheimer''s Disease. Future research should focus on reducing this decline early in the course of the disease in order to maintain physical independence for as long as possible. [Copyright &y& Elsevier]

Background Foot posture has been postulated as a risk factor for overuse injuries of the knee, however the link between foot posture and knee joint function is unclear. The aims of this study were to: (i) compare knee adduction moment and knee joint rotations between normal, planus and cavus foot posture groups, and (ii) to determine the relationship between rearfoot and midfoot joint rotations and knee adduction moment magnitude. Methods Rotation of the knee, rearfoot and midfoot was evaluated in 97 healthy adults that were classified as normal ( n = 37), cavus ( n =30 ) or planus ( n = 30) for the Foot Posture Index, Arch Index and normalised navicular height. One way analyses of variance were used to compare tri-planar knee joint rotation, knee adduction moment peak variables and knee adduction angular impulse between foot posture groups. Pearson's correlation coefficient was used to investigate the association between rearfoot and midfoot joint rotation during initial contact phase and the magnitude of 1st knee adduction moment peak. Findings The planus group displayed significantly greater external rotation angle at heel contact compared to both normal and cavus groups. The planus groups also displayed greater extension at heel contact and sagittal plane flexion range of motion during propulsion and early swing compared to the cavus group. Otherwise, differences between groups were characterised by small effect sizes. There was no association between rearfoot or midfoot joint rotations and knee adduction moment. Interpretation These findings suggest that in healthy individuals, foot posture and foot joint rotations do not substantially influence knee joint rotations and knee adduction moment while walking at a comfortable pace. [ABSTRACT FROM AUTHOR]

Abstract: Foot problems are highly prevalent in older people. To treat such problems in this age-group prefabricated (‘off-the-shelf’) foot orthoses are frequently prescribed. However, such devices are susceptible to material compression and deformation, which may reduce their effectiveness over time. Therefore, the aim of this study was to compare the pressure-redistributing properties of new prefabricated orthoses to orthoses worn for at least 12 months. Thirty-one adults (10 males, 21 females) aged over 65 years (mean 75.4, SD 5.2) participated. Plantar pressure data were collected under the rearfoot, midfoot and forefoot using the Pedar® in-shoe system while participants walked along an 8m walkway wearing shoes only, new orthoses and old orthoses (orthoses were full length, dual-density prefabricated Formthotic™ devices). Compared to the shoe-only condition, both the new and old orthoses produced significant reductions in peak pressure and maximum force in the rearfoot with corresponding increases in force and contact area in the midfoot. Compared to the new orthoses, the old orthoses exhibited small but significant increases in peak pressure in the rearfoot (6%, p =0.001) and maximum force in the rearfoot (5%, p <0.001) and forefoot (2%, p =0.032). These findings indicate that the prefabricated orthoses evaluated in this study are only slightly less effective at redistributing plantar pressure after at least 12 months of wear. [Copyright &y& Elsevier]