Impact of foot modeling on the quantification of the effect of total ankle replacement: A pilot study

BackgroundKinematic and kinetic foot models showed that computing ankle joint angles, moments and power with a one-segment foot modeling approach alters kinematics and tends to overestimate ankle joint power. Nevertheless, gait studies continue to implement one-segment foot models to assess the effect of total ankle replacement.Research questionThe objective of this pilot study was to investigate the effect of the foot modeling approach (one-segment versus multi-segment) on how total ankle replacement is estimated to benefit or degrade the patient’s biomechanical performance.MethodsTen subjects with post-traumatic ankle osteoarthritis scheduled for total ankle replacement and 10 asymptomatic subjects were recruited. A one-segment and a multi-segment foot model were used to calculate intrinsic foot joints kinematics and kinetics during gait. A linear mixed model was used to investigate the effect of the foot model on ankle joint kinematic and kinetic analysis and the effect of total ankle replacement.ResultsDifferences in range of motion due to the foot model effect were significant for all the gait subphases of interest except for midstance. Peak power generation was significantly overestimated when computed with the one-segment foot model. Ankle and shank-calcaneus joint dorsi-/plantarflexion range of motion did not increase post-operatively except during the loading response phase. A significant ‘group’ effect was found for stance and pre-swing phase range of motion, with total ankle replacement patients showing lower range of motion values than controls for dorsi/plantarflexion.SignificanceThe outcome of this study showed that the ‘foot model’ had a significant effect on estimates of range of motion and power generation. The findings in our study therefore emphasize the clinical interest of multi-segment foot modeling when assessing the outcome of a therapeutic intervention.     

The immediate effects of sensorimotor foot orthoses on foot kinematics in healthy adults

BackgroundSensorimotor foot orthoses is an alternative concept, which in addition to mechanical effects, are designed to change muscle activation by altering sensory input to the plantar surface of the foot. However, there is little evidence of how these affect the kinematics of the foot during gait.Research questionThe aim of the study was to explore the immediate effect of calcaneal medial heel bars and retrocapital bars on foot kinematics during the stance phase of gait.MethodsKinematic data were collected from 32 healthy individuals using an eight camera motion capture system and a six-degrees-of-freedom multi-segment foot model in three different orthotic conditions; calcaneal medial heel bar, retrocapital bar, and no orthosis. Vector field statistical analysis was performed to explore the effect of the orthotic conditions over the kinematic time series curves during stance phase. Peak median and interquartile ranges were also reported during the different phases of stance.ResultsThe calcaneal medial bar significantly decreased rearfoot eversion for the majority of the stance phase and compensatory increased midfoot eversion during the entire stance phase compared to the no orthosis condition. The retrocapital bar rotated the foot externally significantly abducting the rearfoot for the entire stance phase and the midfoot for the majority of stance phase.SignificanceThe calcaneal medial heel bar and retrocapital bar significantly altered the foot kinematics in a way that may benefit patients with abnormal pronation and intoeing gait.     

Compensation of stochastic time-continuous perturbations during walking in healthy young adults: An analysis of the structure of gait variability

BackgroundDuring everyday locomotion, we cope with various internal or external perturbations (e.g. uneven surface). Uncertainty exists on how unpredictable external perturbations increase noise within the motor system and if they are compensated by employing covariation of the limb joints or rather due to decreased sensitivity of an altered posture.Research questionDo continuous stochastic perturbations affect the structure of gait variability in young and healthy adults?MethodsIn a cross-over study, gait kinematics of 21 healthy young sports students were registered during treadmill walking with and without continuous stochastic perturbations. Using the TNC method, the following aspects were analyzed: (a) the sensitivity of body posture to perturbations (‘tolerance’) decreasing gait variability, (b) the unstructured motor ‘noise’ increasing gait variability and (c) the amount of ‘covariation’ of the limb joints.ResultsCompared to normal walking, gait variability was significantly increased (p < .001) during walking with perturbations. The negative effect of noise was partly compensated by improved ‘covariation’ of leg joints (p < .001). The aspect ‘tolerance’ had a small effect on increasing gait variability during stance phase (p < .001) and decreasing gait variability during swing phase (p < .001).SignificanceIncreased motor noise due to external perturbations is partly compensated by improved covariation of the limb joints. However, the effect of an altered posture slightly affects gait variability. Further studies should focus on different populations (e.g. older participants) to see if they use the same mechanism (improved covariation) to compensate for stochastic perturbations.     

Comparing the effects of adapting to a weight on one leg during treadmill and overground walking: A pilot study

BackgroundLocomotor adaptation has been suggested as a way to improve gait symmetry in individuals post-stroke. Most perturbation methods utilize costly, specialized equipment. The use of a unilateral leg weight may provide a low cost, clinically translatable alternative. Furthermore, previous studies have suggested that adaptation context may affect movement outcomes. The purpose of this study was to assess the ability of a unilaterally applied ankle weight to drive locomotor adaptation and determine the effect of context (treadmill versus overground) in young, non-disabled participants.MethodsEighteen young non-disabled adults were randomly assigned to receive 10 min of walking on a treadmill with a weight (TG), overground with a weight (OG) or as a control on a treadmill/overground without a weight (CG). Outcomes measured before, during and after adaptation were: step length symmetry, single limb support symmetry and gait speed.ResultsAfter adding the weight, single limb support immediately became asymmetrical for all participants without changes in step length symmetry. After walking for 10 min, TG step length became asymmetrical. After weight removal, both TG and OG had increased step length asymmetry. TG decreased single limb support asymmetry while OG did not. After walking overground without the weight, walking parameters eventually returned to baseline in both weighted groups. The control group showed no changes.ConclusionA unilaterally applied ankle weight appears able to cause gait adaptation in young, non-disabled participants. However different adaptive changes in the gait pattern are made by the nervous system when the perturbation is applied in different contexts.     

Extrinsic foot muscle forces and joint contact forces in flexible flatfoot adult with foot orthosis: A parametric study of tibialis posterior muscle weakness

BackgroundThe posterior tibialis tendon dysfunction (PTTD) is typically associated with progressive flatfoot deformity, which could be alleviated with foot orthosis. However, the evaluation of tibialis posterior (TP) weakness on lower limb mechanics of flatfoot adults with foot orthoses is scarce and requires further investigation.Research questionThis study aimed to examine the effects of TP weakness on lower limb mechanics in flatfoot adults with foot orthosis through gait analysis and musculoskeletal modelling.MethodsFifteen young adults with flatfoot were recruited from University to perform a gait experiment with and without foot orthoses. Data collected from the motion capture system were used to drive the musculoskeletal modelling for the estimation of the joint force and extrinsic muscle forces of the lower limb. A parametric analysis was conducted by adjusting the TP muscle strength from 40 % to 100 %. Two-way repeated measures ANOVA was used to compare the peak extrinsic foot muscle forces and joint forces among different levels of TP weakness and insole conditions.ResultsTP weakness significantly increased ankle joint force superoinferiorly (F = 125.9, p < 0.001) and decreased anteroposteriorly (F = 125.9, p < 0.001), in addition to a significant increase in the muscle forces of flexor hallucis longus (p < 0.001) and flexor digitorum longus (p < 0.001). Besides, the foot orthosis significantly reduced most peak muscle forces whilst significantly reduced the second peak knee force and peak ankle force compared to the control condition (F = 8.79–30.9, p < 0.05).SignificanceThe increased extrinsic foot muscle forces (flexor hallucis longus and flexor digitorum longus) and ankle joint forces in the TP weakness condition indicated that TP weakness may induce compensatory muscle activation and attenuated joint load. The abnormal muscle and joint mechanics in flatfoot adults with TP weakness might be restored by the orthosis.     

Effect of Kinesio Taping on gastrocnemius activity and ankle range of movement during gait in healthy adults: A randomized controlled trial

ObjectiveTo examine the effect of KT on gastrocnemius surface electromyography (SEMG) activity and ankle range of motion during walking in healthy subjects.DesignRandomized controlled trial, with concealed allocation and assessor blinding.SettingUniversity Biomechanics Laboratory.ParticipantsThirty six healthy physiotherapy students were randomized to KT or control group.Outcome MeasuresAt baseline and immediately after 72 h with the tape in situ: amplitude of LG SEMG activity during the stance phase, duration of the LG activity, onset and offset times of LG activity, ankle plantar- and dorsiflexion peaks, and the cadence of gait.ResultsANOVA revealed a significant time × intervention interaction effect across two variables: duration of LG activation, F(1, 33) = 4.71, p = .037, η = .015; and onset F(1, 33) = 7.92, p = .008, η = .037. KT group showed significantly shorter duration of the LG activity as compared with control, and similar results were observed when comparing the onset of LG activation. No statistically significant differences between both groups were noted in the rest of the outcomes.ConclusionKT does significantly shorten the duration of the LG activity during gait when applied 72 h in healthy adults. However, this result was not accompanied by a significant reduction in the amplitude of LG SEMG activity.     

Acute effects of axial loading on postural control during walking and turning in people with multiple sclerosis: A pilot study

BackgroundImpaired sensory integration is heavily involved in gait control and accentuates fall risk in individuals with multiple sclerosis (MS). While axial loading has been found beneficial, little is known about the effect of non-specific axial loads on gait parameters and mobility tasks in those with MS. Research Question: What are the effects of non-specific axial loading via weighted vests on walking and turning in those with MS.MethodsTwelve participants with MS and eleven age- and gender-matched healthy controls participated in a cross-sectional study. All participants completed five trials of continuous walking with turns wearing weighted vests at 0%, 2%, 4%, 5%, and then 0% of their body weight. Gait parameters were measured using wireless inertial sensors. A 2 (group) x 5 (vest weight) multivariate analysis of variance (MANOVA) was performed to determine any significant differences between groups and across weighted vests for each gait variable. Post-hoc analysis and paired t-tests with corresponding effect sizes were also conducted.ResultsA significant between groups main effect was found for group (F (6100) = 14.74, p = .000) in multiple gait parameters (p < 0.05), although no significant main effect was found for weighted vest. Within group analyses indicated significantly increased cadence and gait speed across varying weighted vests for both MS and control groups (p < 0 >05). Increased vest weight from 0%PRE to 2% also had large effect on shortening double support time and increasing stride length in the MS group.SignificanceThis study provided preliminary evidence that non-specific axial loads of varying weights appear to improve certain gait parameters. As such, this modality may offer mobility benefit and serve as an accessible home-based intervention alternative aimed at improving walking in individuals with MS.     

Efficacy of lateral stair walking training in patients with chronic stroke: A pilot randomized controlled study

BackgroundPatients with chronic stroke have reduced capacity for performing activities of daily living (ADLs) and are at increased risk for falls during walking due to long-term changes to muscle tone and force, as well as movement control.Research questionTo investigate the efficacy of lateral stair walking training on muscle strength of affected lower extremities, balance, ADLs, and gait ability in patients with chronic stroke.MethodsThe experimental group received 15 min of lateral stair walking exercise along with 15 min of traditional physiotherapy, whereas the control group received only traditional physiotherapy for 30 min. Both groups received the intervention once a week for 12 weeks. Outcome measurements included muscle strength, postural assessment scale for stroke patients (PASS), Fugal–Meyer assessment for lower extremity (FMA-LE), Barthel index (BI), timed up and go test (TUG), and the gait parameters which were determined by the Reha-Watch system.ResultsA total of 24 participants completed the study. The experimental group showed significant improvements in hip extensor, flexor, and abductor strength of the affected limb, FMA-LE, BI, TUG, and gait parameters of stride length, velocity, and cadence. Significant differences in affected limb ankle plantar strength (p = 0.024), PASS (p = 0.017), BI (p = 0.039), TUG (p = 0.049), and gait velocity (p < 0.001) were observed between the 2 groups.SignificanceLateral stair walking training alongside physical therapy resulted in significant improvements in hip muscle strength and gait parameters in patients with chronic stroke. Our results support the incorporation of lateral stair walking training into clinical rehabilitation programs. Lateral stair walking training in patients with chronic stroke can be used as an effective treatment to improve gait, balance performance, and ADLs.     

The effects of ankle braces and taping on lower extremity running kinematics and energy expenditure in healthy,non-injured adults

Ankle braces and taping are commonly used to prevent ankle sprains and allow return to play following injury, however, it is unclear how passive restriction of joint motion may effect running gait kinematics and energy expenditure during exercise. The purpose of this study was to determine the effect of different types of ankle supports on lower extremity kinematics and energy expenditure during continuous running. Thirteen healthy physically active adults ran at self-selected speed on the treadmill for 30 min in four different ankle support conditions: semi-rigid hinged brace, lace-up brace, tape and control. Three-dimensional lower extremity kinematics and energy expenditure were recorded every five minutes. The semi-rigid hinged brace was most effective in restricting frontal plane ankle motion. The lace-up brace and tape restricted sagittal plane ankle motion, while semi-rigid hinged bracing allowed for normal sagittal plane ankle kinematics. Kinematic changes from all three ankle supports were generally persistent through 25–30 min of exercise. Only tape influenced knee kinematics, limiting flexion velocity and flexion-extension excursion. Small but significant increased in energy expenditure was found in tape and semi-rigid hinged brace conditions; however, the increases were not to any practically significant level (<0.5 kcal/min).     

O 089 - A soft robotic exosuit assisting the paretic ankle in patients post-stroke: Effect on muscle activation during overground walking

This study compared overground walking with and without exosuit assistance in post-stroke patients. Exosuit-assisted walking was found to improve paretic propulsion and ground clearance during swing, two common gait deviations in stroke patients. No changes in leg muscle activity was found, motivating further study of the exosuit as a tool for gait training during stroke rehabilitation.     

The effects of pole walking on health in adults: A systematic review

The aim of this systematic review was to summarize the effects of pole walking (PW) programs on physical and psychosocial health. Randomized controlled and controlled trials were identified from literature searches in PubMed, Cochrane library, EMBASE, SPORTdiscuss, CINAHL and PEDRO. A total of 14 articles from 13 studies met the inclusion criteria. Eleven of the included studies had a quality score of 50% or higher. Most studies included mid to older aged men and women in clinical populations with various medical conditions. Only two studies included nonclinical populations. The majority of the PW programs consisted of supervised group sessions performed two to three times weekly for 8 weeks or longer. Most studies investigated the effects of PW on both physical and psychosocial health and the majority examined effects on four to five outcomes. The effects of PW on cardiorespiratory fitness were most extensively studied. The most frequently examined psychosocial measure was quality of life. All studies reported at least one beneficial effect of PW compared with the control group. The results of this systematic review indicate that PW programs have some beneficial effects on both physical and psychosocial health in adults with and without clinical conditions.     

Effects of bi-axial ankle strengthening on muscle co-contraction during gait in chronic stroke patients: A randomized controlled pilot study

IntroductionAnkle dysfunction in patients with stroke is a common but serious cause of balance and gait impairments. However, comprehensive paretic ankle training seldom exists. Thus, we investigated the effects of a bi-axial ankle muscle training program using visual feedback as a means to improve ankle strength and performance of functional activities in patients with stroke.MethodsThis study was a randomized controlled pilot trial with concealed allocation and assessor blinding and intention-to-treat analysis. Twenty-five patients with stroke and difficulty in walking (e.g., foot drop) or ankle muscle weakness receiving inpatient rehabilitation were included. The experimental group underwent ankle muscle training consisting of passive stretching, control of ankle muscles, and active-resistive strengthening using visual feedback for 40 min per day, 5 times per week for 4 weeks. The control group underwent ankle-related physical therapy, including ankle range-of-motion exercises. The amount of time for training was equal between the two groups. The outcome measurements were isometric ankle contraction force to assess the strength of ankle muscles, ankle proprioception, Fugl–Meyer lower extremity score, Berg balance scale score, walking speed, and ankle co-contraction index to assess muscle efficiency during gait.ResultsThe analysis revealed significant between-group differences in the ankle muscle strength in each direction (P < 0.05), Fugl–Meyer score (P < 0.01), and stance-phase co-contraction index (P < 0.05). After training, the experimental group displayed significant within-group differences in the strength of the ankle muscles in each direction (P < 0.01), ankle proprioception (P < 0.05), and walking speed (P < 0.05).ConclusionsOur findings demonstrate the significant short-term effects of ankle muscle training on strength, walking speed, and muscle efficiency in patients with chronic stroke.     

Immediate and short-term effects of wearing a single textured insole on symmetry of stance and gait in healthy adults

Asymmetry of standing balance and gait are common in individuals with neurological or musculoskeletal disorders and achieving symmetrical stance and gait is an important goal of rehabilitation. The aim of the study was to investigate if asymmetry of stance and gait observed immediately after the start of using a single textured insole remains during longer use of the insole. Ten young healthy adults walked in two different conditions: with a textured insole positioned in the left shoe or without the insole. Weight bearing, gait, and perceived level of discomfort were evaluated before using a textured insole, immediately after being provided with the insole, and after walking for 10 min with the insole. The center of pressure (COP) trajectory was calculated for the right and left foot in the insole and no-insole conditions. Asymmetry of stance and gait was present immediately after the start of using a textured insole (p < 0.05) but was not evident after 10 min of wearing the insole. The COP trajectory of the right foot after being provided with the left insole was significantly greater compared with walking with no insole (p < 0.05). Gait velocity, cadence, and the COP trajectory of the left foot were not affected by the use of the insole. The outcome of the study provides a background for the investigation of the effect of using a textural insole in gait rehabilitation.     

The effects of object height and visual information on the control of obstacle crossing during locomotion in healthy older adults

In order to safely avoid obstacles, humans must rely on visual information regarding the position and shape of the object obtained in advance. The present study aimed to reveal the duration of obstacle visibility necessary for appropriate visuomotor control during obstacle avoidance in healthy older adults. Participants included 13 healthy young women (mean age: 21.5 ± 1.4 years) and 15 healthy older women (mean age: 68.5 ± 3.5 years) who were instructed to cross over an obstacle along a pressure-sensitive pathway at a self-selected pace while wearing liquid crystal shutter goggles. Participants were evaluated during three visual occlusion conditions: (i) full visibility, (ii) occlusion at T-1 step (T: time of obstacle crossing), and (iii) occlusion at T-2 steps. Toe clearances of both the lead and trail limb (LTC and TTC) were calculated. LTC in the occlusion at T-2 steps condition was significantly greater than that in other conditions. Furthermore, a significant correlation was observed between LTC and TTC in both groups, regardless of the condition or obstacle height. In the older adult group alone, step width in the occlusion at T-2 steps condition increased relative to that in full visibility conditions. The results of the present study suggest that there is no difference in the characteristics of visuomotor control for appropriate obstacle crossing based on age. However, older adults may exhibit increased dependence on visual information for postural stability; they may also need an increased step width when lacking information regarding their positional relationship to obstacles.     

Acute effects of anesthetic lumbar spine injections on temporal spatial parameters of gait in individuals with chronic low back pain: A pilot study

This study examined whether epidural injection-induced anesthesia acutely and positively affected temporal spatial parameters of gait in patients with chronic low back pain (LBP) due to lumbar spinal stenosis. Twenty-five patients (61.7 ± 13.6 years) who were obtaining lumbar epidural injections for stenosis-related LBP participated. Oswestry Disability Index (ODI) scores, Medical Outcomes Short Form (SF-36) scores, 11-point Numerical pain rating (NRS_pain) scores, and temporal spatial parameters of walking gait were obtained prior to, and 11-point Numerical pain rating (NRS_pain) scores, and temporal spatial parameters of walking gait were obtained after the injection. Gait parameters were measured using an instrumented gait mat. Patients received transforaminal epidural injections in the L1-S1 vertebral range (1% lidocaine, corticosteroid) under fluoroscopic guidance. Patients with post-injection NRS_pain ratings of “0” or values greater than “0” were stratified into two groups: 1) full pain relief, or 2) partial pain relief, respectively. Post-injection, 48% (N = 12) of patients reported full pain relief. ODI scores were higher in patients with full pain relief (55.3 ± 21.4 versus 33.7 12.8; p = 0.008). Post-injection, stride length and step length variability were significantly improved in the patients with full pain relief compared to those with partial pain relief. Effect sizes between full and partial pain relief for walking velocity, step length, swing time, stride and step length variability were medium to large (Cohen’s d > 0.50). Patients with LBP can gain immediate gait improvements from complete pain relief from transforaminal epidural anesthetic injections for LBP, which could translate to better stability and lower fall risk.     

An exploration of the effects of prefabricated and customized insoles on lower limb kinetics and kinematics during walking,stepping up and down tasks: A time series analysis

BackgroundPrefabricated and customized insoles are used in clinical practice to reduce foot pronation. Although data exist on the effects at key points within the stance phase, exploring the impact of different insoles using time series analysis may reveal more detail about their efficacy.Research questionWhat are the effects revealed by a time series analysis of arch-supported prefabricated insoles (PREFABRICATED) versus arch-supported prefabricated insoles customized with a 6º medial wedge (CUSTOMIZED) on the lower limb biomechanics during walking, stepping up and down tasks in individuals with pronated feet?MethodsNineteen individuals with excessive foot pronation performed walking, stepping up and down tasks using three insoles: CONTROL (flat insole), CUSTOMIZED, and PREFABRICATED. Angles and moments of ankle and knee coronal and hip transverse planes were compared between conditions using statistical parametric mapping (SPM).ResultsFor walking, CUSTOMIZED reduced ankle eversion moment compared to CONTROL during midstance and PREFABRICATED during propulsion. CUSTOMIZED decreased KAM during midstance and propulsion compared to PREFABRICATED. Compared to CONTROL, CUSTOMIZED and PREFABRICATED reduced hip internal rotation during propulsion and loading response, respectively. CUSTOMIZED decreased eversion movement during midstance and propulsion for the stepping up task. PREFABRICATED reduced eversion movement during midstance in comparison to CONTROL. For the stepping down task, CUSTOMIZED increased eversion movement during propulsion compared to PREFABRICATED. CUSTOMIZED reduced hip internal rotation angle for stepping up task during propulsion, decreased medial rotation movement during midstance compared to CONTROL, and reduced medial rotation during midstance compared to PREFABRICATED. CUSTOMIZED increased KAM for stepping up and down tasks during propulsion.SignificanceThese findings suggest that both CUSTOMIZED and PREFABRICATED reduce foot pronation. However, non-local effects, such as changes in KAM and hip internal rotation, were seen only in the CUSTOMIZED. Therefore, CUSTOMIZED may be preferable if the objective is to modify the knee and hip mechanics.     

The effects of textured materials on static balance in healthy young and older adults: A systematic review with meta-analysis

BackgroundStanding on textured materials can improve static balance, potentially by modulating somatosensory inputs from the soles of the feet.Research questionTo synthesise and quantify the immediate effects of textured materials on static balance in healthy young and older adults.MethodsPrimary outcomes were the centre of pressure (COP) displacement and velocity, during eyes open and eyes closed conditions. Ten crossover studies (n = 318, 58% female) met the inclusion criteria. A random effects meta-analysis model derived pooled standardised mean differences (SMD; Hedges g) to quantify the effects of textured materials. Heterogeneity was quantified with the tau-statistic (τ). A 95% prediction interval quantified the likely range of true effects on COP outcomes in similar future studies.ResultsThere was a small to moderate beneficial effect for textured materials vs control conditions in: COP displacement during both eyes open (SMD: 0.29; 95% CI -0.06 to 0.64; τ = 0.32) and eyes closed (SMD: 0.75; 95% CI 0.18 to 1.33; τ = 0.55). A trivial to small beneficial effect was observed in COP velocity during eyes open (SMD: 0.14; 95% CI -0.14 to 0.43; τ = 0.18) and eyes closed (SMD: 0.20; 95% CI 0.01 to 0.40; τ = 0.18) for textured materials. The 95% prediction intervals showed texture may not consistently provide beneficial results across studies for all outcomes: COP displacement EC (-0.61 to 2.12), EO (-0.54 to 1.12), COP velocity EC (-0.27 to 0.68) and EO (-0.44 to 0.73).SignificanceOverall, textured materials improved balance, but these effects were heterogeneous. This research may therefore inform applied investigations into balance improvements for healthy populations, for example, in functional movements and sports.     

Ultrasonography versus computed tomography in evaluation of the femoral trochlear groove morphology: a pilot study on healthy, young volunteers

The aim of the study was to verify the efficacy of ultrasonography (US) in evaluating the morphology of normal trochlea, especially the sulcus angle and the trochlear depth, in comparison with computed tomography (CT) (gold standard). The knees of 11 asymptomatic volunteers were subjected to US and CT evaluation of the same section planes and the results were compared. For statistical evaluation Spearman's correlation coefficient analysis was used. A statistically significant correlation was found between the two diagnostic procedures (sulcus angle: r = 0.820; trochlear depth: r = 0.802; Spearman's correlation coefficient) and the intra-observer variability for the US measurements (sulcus angle: r = 0.966; trochlear depth: r = 0.914; Spearman's correlation coefficient). The mean value of sulcus angle and trochlear depth was 132 ° and 5.6 mm, respectively, similar to those reported in the literature. We conclude that evaluation by US of both sulcus angle and trochlear depth is as reproducible and sensitive as that performed with CT. Received 22 January 1996; Revision received 11 April 1997; Accepted 22 May 1997     

The effect of a dual task on gait speed in community dwelling older adults: A systematic review and meta-analysis

Background and purposeReduced walking speed in older adults is associated with adverse health outcomes. This review aims to examine the effect of a cognitive dual-task on the gait speed of community-dwelling older adults with no significant pathology affecting gait.Data sources and study selectionElectronic database searches were performed in, Web of Science, PubMed, SCOPUS, Embase and psychINFO. Eligibility and methodological quality was assessed by two independent reviewers. The effect size on gait speed was measured as the raw mean difference (95% confidence interval) between single and dual-task performance. Pooled estimates of the overall effect were computed using a random effects method and forest plots generated.Data extraction and data synthesis22 studies (27 data sets) with a population of 3728 were reviewed and pooled for meta-analysis. The mean walking speed of participants included in all studies was >1.0 m/s and all studies reported the effect of a cognitive dual-task on gait speed. Sub-analysis examined the effect of type of cognitive task (mental-tracking vs. verbal-fluency). Mean single-task gait speed was 1.21 (0.13) m/s, the addition of a dual-task reduced speed by 0.19 m/s to 1.02 (0.16) m/s (p < 0.00001), both mental-tracking and verbal-fluency tasks resulted in significant reduction in gait speed.Limitations and conclusionThe cross-sectional design of the studies made quality assessment difficult. Despite efforts, high heterogeneity remained, possibly due to participant characteristics and testing protocols. This meta-analysis shows that in community-dwelling older adults, the addition of a dual-task significantly reduces gait speed and may indicate the value of including dual-task walking as part of the standard clinical assessment of older people.