Changes In Walking Speed Research Articles

Effect of a plantar perceptual learning task on walking stability in the elderly: a randomized controlled trial

Objective: To determine whether the plantar perceptual learning task, using a hardness discrimination training, efficiently improves walking stability in the elderly. Design: A randomized controlled trial. Setting: Elder day-care center. Participants: Eighty-six elderly people (73.84 SD 5.98 years) who went to an elder day-care center were randomly assigned evenly to either an intervention or a control group. Intervention: The intervention group performed a task to discriminate hardness differences while standing on sponge mats of different levels of hardness. The control group underwent the same task except that they were not instructed to discriminate hardness levels of the mats. The tasks were carried out over a four-week period for 10 days for both groups. Outcome measures: Outcome was assessed by determining root mean squares of trunk acceleration during walking. Results: Plantar perception was significantly improved in the intervention group after training (F = 26.24, p < 0.01). In addition, changes in root mean square values of acceleration were significantly greater after training in the intervention group (medial–lateral, 0.36 SD 0.26; vertical, 0.32 SD 0.24; anterio–posterior, 0.26 SD 0.24) than in the control group (medial–lateral, 0.14 SD 0.28, vertical, 0.16 SD 0.35, anterio–posterior, 0.12 SD 0.29) (p < 0.05). Changes in walking speed were not significantly different (p = 0.13) between the intervention (0.06 SD 0.13) and control groups (0.02 SD 0.14). Conclusion: The plantar perceptual learning task might efficiently stabilize postural control during walking in the elderly.

Sensitivity of joint moments to changes in walking speed and body-weight-support are interdependent and vary across joints

We investigated the effect of simultaneous changes in body-weight-support level and walking speed on mean peak internal joint moments at the ankle, knee and hip. We hypothesized that observed changes in these joint moments would be approximately linear with both body-weight-support and walking speed and would be similar across joints. Kinematic and kinetic data were collected from 8 unimpaired adult subjects walking on an instrumented treadmill while wearing a dynamically controlled overhead support harness. Subjects walked with four levels of body-weight-support (0%, 20%, 40%, and 60% of bodyweight) at three walking speeds (0.4, 0.6, and 0.8 statures/s, ranging on average from 0.7 to 1.4m/s). Data were used to calculate mean peak joint moments across subjects for each condition. In general, subjects’ mean peak joint moments decreased linearly with decreasing walking speed and with increasing body-weight-support, except the knee extension moment, which showed a quadratic relationship with walking speed and no significant change with body-weight-support. All joint moments, with the exception of knee extension, showed a significant interaction effect between walking speed and body-weight-support, indicating that the sensitivity of these joint moments to changes in these variables was interdependent. In most cases, the ankle and hip extension moments showed the largest sensitivity to walking speed. The ankle moment was observed to have the greatest sensitivity to body-weight-support. This finding, that altering walking speed and body-weight-support level results in non-uniform changes in peak moments across joints, suggests that further research is warranted to establish the set of combined speed and support conditions that produce motor patterns supportive of normal gait retraining.

Simple robot suggests physical interlimb communication is essential for quadruped walking

Quadrupeds have versatile gait patterns, depending on the locomotion speed, environmental conditions and animal species. These locomotor patterns are generated via the coordination between limbs and are partly controlled by an intraspinal neural network called the central pattern generator (CPG). Although this forms the basis for current control paradigms of interlimb coordination, the mechanism responsible for interlimb coordination remains elusive. By using a minimalistic approach, we have developed a simple-structured quadruped robot, with the help of which we propose an unconventional CPG model that consists of four decoupled oscillators with only local force feedback in each leg. Our robot exhibits good adaptability to changes in weight distribution and walking speed simply by responding to local feedback, and it can mimic the walking patterns of actual quadrupeds. Our proposed CPG-based control method suggests that physical interaction between legs during movements is essential for interlimb coordination in quadruped walking.

The Dynamic Relationship Between Physical Function and Cognition in Longitudinal Aging Cohorts

On average, older people remember less and walk more slowly than do younger persons. Some researchers argue that this is due in part to a common biologic process underlying age-related declines in both physical and cognitive functioning. Only recently have longitudinal data become available for analyzing this claim. We conducted a systematic review of English-language research published between 2000 and 2011 to evaluate the relations between rates of change in physical and cognitive functioning in older cohorts. Physical functioning was assessed using objective measures: walking speed, grip strength, chair rise time, flamingo stand time, and summary measures of physical functioning. Cognition was measured using mental state examinations, fluid cognition, and diagnosis of impairment. Results depended on measurement type: Change in grip strength was more strongly correlated with mental state, while change in walking speed was more strongly correlated with change in fluid cognition. Examining physical and cognitive functioning can help clinicians and researchers to better identify individuals and groups that are aging differently and at different rates. In future research, investigators should consider the importance of identifying different patterns and rates of decline, examine relations between more diverse types of measures, and analyze the order in which age-related declines occur.

2P1-E03 前後に振動する能動的な揺動質量を持つ連結型リムレスホイールの歩行解析(受動歩行ロボット(2))

This paper investigates the gait properties of a passive combined rimless wheel with an active wobbling mass that vibrates backward and forward in the body frame. First, we develop the mathematical model and numerically analyze the change in walking speed with respect to the frequency of the wobbling mass. Second, we perform experimental case study and validate the results obtained.

Minimal Clinically Important Difference for Comfortable Speed as a Measure of Gait Performance in Patients Undergoing Inpatient Rehabilitation after Stroke

[Purpose] The purpose of this retrospective study was to determine the minimal clinically important difference for comfortable gait speed for patients with stroke. [Subjects] Data were analyzed from 35 patients undergoing inpatient rehabilitation. [Methods] Two characteristics of gait were measured, assistance required and comfortable gait speed. Patients were grouped as either experiencing or not experiencing a decrease of 2 or more levels of assistance required over the course of rehabilitation. Receiver operating characteristic curve analysis was used to identify the change in gait speed that best differentiated between patients who did and did not experience the requisite decrease in assistance required for gait. [Results] Twenty-one patients decreased 2 or more levels of assistance whereas 14 did not. Walking speed increased significantly more in the group who experienced a decrease in assistance of at least 2 levels. The receiver operating characteristic curve analysis showed a change in walking speed of 0.13 m/s best distinguished between patients who did versus did not experience a reduction in assistance required. [Conclusion] An improvement in gait speed of 0.13 m/s or more is clinically important in patients with stroke.

2P1-E06 四脚準受動的動歩行における脚の振り運動の解析(受動歩行ロボット(2))

In this paper, quadrupedal quasi-passive dynamic walking robot driven by a rocking motion has been investigated. Experiment shows that the robot can walk on the level ground and also that walking speed changes depending on a frequency of the rocking motion. Moreover, it is revealed that there is an interrelation between walking speed and leg swing motion.

Expression of emotion in the kinematics of locomotion

Here, we examine how different emotions-happiness, fear, sadness and anger-affect the kinematics of locomotion. We focus on a compact representation of locomotion properties using the intersegmental law of coordination (Borghese etal. in J Physiol 494(3):863-879, 1996), which states that, during the gait cycle of human locomotion, the elevation angles of the thigh, shank and foot do not evolve independently of each other but form a planar pattern of co-variation. This phenomenon is highly robust and has been extensively studied. The orientation of the plane has been correlated with changes in the speed of locomotion and with reduction in energy expenditure as speed increases. An analytical model explaining the conditions underlying the emergence of this plane and predicting its orientation reveals that it suffices to examine the amplitudes of the elevation angles of the different segments along with the phase shifts between them (Barliya etal. in Exp Brain Res 193:371-385, 2009). We thus investigated the influence of different emotions on the parameters directly determining the orientation of the intersegmental plane and on the angular rotation profiles of the leg segments, examining both the effect of changes in walking speed and effects independent of speed. Subjects were professional actors and naïve subjects with no training in acting. As expected, emotions were found to strongly affect the kinematics of locomotion, particularly walking speed. The intersegmental coordination patterns revealed that emotional expression caused additional modifications to the locomotion patterns that could not be explained solely by a change in speed. For all emotions except sadness, the amplitude of thigh elevation angles changed from those in neutral locomotion. The intersegmental plane was also differently oriented, especially during anger. We suggest that, while speed is the dominant variable allowing discrimination between different emotional gaits, emotion can be reliably recognized in locomotion only when speed is considered together with these kinematic changes.

Locomotor Rehabilitation of Individuals With Chronic Stroke: Difference Between Responders and Nonresponders

ObjectivesTo identify the clinical measures associated with improved walking speed after locomotor rehabilitation in individuals poststroke and how those who respond with clinically meaningful changes in walking speed differ from those with smaller speed increases. DesignA single group pre-post intervention study. Participants were stratified on the basis of a walking speed change of greater than (responders) or less than (nonresponders) .16m/s. Paired sample t tests were run to assess changes in each group, and correlations were run between the change in each variable and change in walking speed. SettingOutpatient interdisciplinary rehabilitation research center. ParticipantsHemiparetic subjects (N=27) (17 left hemiparesis; 19 men; age: 58.74±12.97y; 22.70±16.38mo poststroke). InterventionA 12-week locomotor intervention incorporating training on a treadmill with body weight support and manual trainers accompanied by training overground walking. Main Outcome MeasuresMeasures of motor control, balance, functional walking ability, and endurance were collected at pre- and postintervention assessments. ResultsEighteen responders and 9 nonresponders differed by age (responders=63.6y, nonresponders=49.0y, P=.001) and the lower extremity Fugl-Meyer Assessment score (responders=24.7, nonresponders=19.9, P=.003). Responders demonstrated an average improvement of .27m/s in walking speed as well as significant gains in all variables except daily step activity and paretic step ratio. Conversely, nonresponders demonstrated statistically significant improvements only in walking speed and endurance. However, the walking speed increase of .10m/s was not clinically meaningful. Change in walking speed was negatively correlated with changes in motor control in the nonresponder group, implying that walking speed gains may have been accomplished via compensatory mechanisms. ConclusionsThis study is a step toward discerning the underlying factors contributing to improved walking performance.

The impact of supplemental n-3 long chain polyunsaturated fatty acids and dietary antioxidants on physical performance in postmenopausal women.

Identify relationships and evaluate effects of long chain polyunsaturated fatty acids (LCPUFA) on frailty and physical performance. Randomized, double blind pilot study. University General Clinical Research Center. 126 postmenopausal women. 2 fish oil (1.2g eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) or 2 placebo (olive oil) capsules per day for 6 months. All participants received calcium and vitamin D supplements. Fatty acid levels, frailty assessment, hand grip strength, 8 foot walk, body composition, medical history and co-morbidities, nutrient intake, and inflammatory biomarkers taken at baseline and 6 months. At baseline, those with greater red blood cell (RBC) DHA and DHA/arachidonic acid (AA) presented with less frailty (r = -0.242, p=0.007 and r = -0.254, p=0.004, respectively). Fish oil supplementation resulted in higher RBC DHA and lower AA compared to baseline and placebo (p<0.001) and an improvement in walking speed compared to placebo (3.0±16 vs. -3.5±14, p=0.038). A linear regression model included age, antioxidant intake (selenium and vitamin C), osteoarthritis, frailty phenotype, and tumor necrosis factor alpha (TNFα). The model explained 13.6% of the variance in the change in walking speed. Change in DHA/AA (p=0.01) and TNFα (p=0.039), and selenium intake (p=0.031) had the greatest contribution to change in walking speed. Physical performance, measured by change in walking speed, was significantly affected by fish oil supplementation. Dietary intake of antioxidants (selenium and vitamin C) and changes in TNFα also contributed to change in walking speed suggesting LCPUFA may interact with antioxidants and inflammatory response to impact physical performance.

Neuromagnetic Activity of the Somatosensory Cortices Associated With Body Weight–Supported Treadmill Training in Children With Cerebral Palsy

It has been previously shown that body weight-supported treadmill training (BWSTT) can improve the walking performance of children with cerebral palsy (CP). Potentially, the sensorimotor experience from BWSTT may facilitate reorganization of the brain areas that are involved in the control of the stepping pattern. We explored whether BWSTT has the potential to promote parallel changes in the motor behavior of children with CP and the activity of the somatosensory cortices. Four children with spastic diplegic CP (age = 13.7 ± 2 years; 3 males and 1 female) who had Gross Motor Function Classification Scores that ranged from III to IV participated in this investigation. The body weight-supported treadmill training was performed twice a week for 6 weeks. Magnetoencephalography brain imaging was used to determine whether the amplitudes of the early latency somatosensory cortical responses changed after BWSTT. Motor behavioral outcomes included changes in walking speed, walking endurance, and lower extremity strength. The neuromagentic source amplitudes were attenuated after BWSTT and were accompanied by faster walking speeds and improved lower extremity strengths. DISCUSSION AND CONCLUSIOINS: These preliminary findings suggest that the BWSTT sensorimotor experience may result in neuroeconomical changes that reduce cortical processing demands in children with CP. Furthermore, these neuroplastic changes may be related to the parallel changes in the walking performance and lower extremity strength of children with CP.

Influence of modified solid ankle-foot orthosis to be used with and without shoe on dynamic balance and gait characteristic in asymptomatic people

Ankle-foot orthoses are usually used in combination with footwear. Shoe design can have a significant effect on kinematics of the lower limb joints and line of action of the ground reaction force during walking. But, ankle-foot orthosis-footwear combination is not appropriate for indoor barefoot walking in some Asian cultures. In this study, we have modified a solid ankle-foot orthosis in order to set it in the same position as a solid ankle-foot orthosis-footwear combination. To investigate the effect of a modified solid ankle-foot orthosis; a solid ankle-foot orthosis which can be locked in different positions on gait and balance performance in comparison with a conventional solid ankle-foot orthosis, a common solid ankle-foot orthosis-shoe combination in asymptomatic adults. Cross sectional. Two standard solid ankle-foot orthoses were manufactured with the ankle joint in neutral position. Then, one of these solid ankle-foot orthoses was modified in order to allow locking in a different alignment. Walk across, limit of stability, and sit-to-stand tests of the balance master system were performed while participants wore the modified solid ankle-foot orthosis aligned in 5°-7° anterior inclination without a shoe and a conventional solid ankle-foot orthosis-shoe combination. There was no significant change in walking speed, step length, and step width with the conventional and modified solid ankle-foot orthoses. In addition, movement velocity and maximum excursion of the center of gravity during the limit of stability test were not different, although the maximal forward excursion of the center of gravity was longer when wearing the modified solid ankle-foot orthosis compared to the conventional solid ankle-foot orthosis-shoe combination (P = 0.000). Sway velocity of the center of gravity did not change during the sit-to-stand test. The results demonstrated that the modified solid ankle-foot orthosis had the same effects as the conventional solid ankle-foot orthosis-shoe combination on the gait and balance performance of asymptomatic adults. Clinical relevance The findings of the present study can be used as the basis for further investigations on the efficacy of the modified solid ankle-foot orthoses in different neuromuscular populations in order to help people who do not wear shoes at home, as is the custom in some Asian cultures.

Biomechanical variables related to walking performance 6-months following post-stroke rehabilitation

BackgroundBody-weight supported treadmill training has been shown to be effective in improving walking speed in post-stroke hemiparetic subjects, and those that have shown improvements generally maintain them after the completion of rehabilitation. However, currently no biomechanical variables are known to be related to those who will either continue to improve or regress in their self-selected walking speed during the 6-month period following rehabilitation. The objective of this study was to identify those biomechanical variables that are associated with subjects who continue (or did not continue) to improve their self-selected walking speed following the completion of rehabilitation. MethodsExperimental kinematic and kinetic data were recorded from 18 hemiparetic subjects who participated in a 6-month follow-up study after completing a 12-week locomotor training program that included stepping on a treadmill with partial body weight support and manual assistance. Pearson correlation coefficients were used to determine which biomechanical variables evaluated during the post-training session were related to changes in self-selected walking speed from post-training to a 6-month follow-up session. FindingsFollowing the completion of rehabilitation, the majority of subjects increased or retained (i.e., did not change) their self-selected walking speed from post-training to the follow-up session. Post-training step length symmetry and daily step activity were positively related to walking speed improvements. InterpretationMotor control deficits that lead to persistent step length asymmetry and low daily step activity at the end of rehabilitation are associated with poorer outcomes six months after completion of the program.

Evaluation of Two Fatigability Severity Measures in Elderly Adults

To document the stability, concurrent validity, and clinical correlates of two fatigability severity measures as recommended by the American Geriatrics Society. Descriptive, cross-sectional. Two independent living and one community senior centers. Forty-three participants, with an average age 85 ± 6. Perceived fatigability severity was quantified by directly asking participants to report change in energy after a standardized 10-minute walk at a self-selected pace. Performance fatigability severity was defined as a ratio of change in walking speed to total distance walked. The walk test was repeated within 2 weeks to assess stability. Total daily physical activity (PA) was measured over 7 consecutive days using a waist-worn accelerometer. Frailty was measured using the Vulnerable Elders Survey interview scale, and gait speed was measured using a standardized 25-feet walk test. The perceived and performance fatigability severity measures were significantly correlated (correlation coefficient (r) = 0.94, P < .001) and stable over two assessments (r = 0.82 and 0.85, P < .001). Both fatigability severity measures were significantly correlated with PA level (r = -0.42 and r = -0.44, respectively, P = .02), frailty (r = 0.47 and 0.53, respectively, P = .001) and gait speed (r = -0.45, P = .003 and r = -0.54, P = .001, respectively). The methodology described in this study permits the calculation of two highly correlated fatigability severity scores, which summarize the relationship between a person's change in self-reported tiredness or change in physical performance and concurrently measured PA. The fatigability severity scores are reproducible and correlated with clinical measures predictive of decline. The methods used to quantify fatigability severity can be implemented during a brief assessment (<15 minutes) and should be useful in the design and evaluation of interventions to increase PA in older adults at risk of functional decline.

Angiotensin‐Converting Enzyme Inhibitor Use by Older Adults Is Associated with Greater Functional Responses to Exercise

To assess the association between angiotensin converting enzyme inhibitors (ACEis) and improvements in the physical function of older adults in response to chronic exercise training. Secondary analysis of the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study, a multisite randomized clinical trial to evaluate the effects of chronic exercise on the physical function of older adults at risk for mobility disability. Four academic research centers within the United States. Four hundred twenty-four individuals aged 70 to 89 with mild to moderate functional impairments categorized for this analysis as ACEi users, users of other antihypertensive drugs, or antihypertensive nonusers. A 12-month intervention of structured physical activity (PA) or health education promoting successful aging (SA). Change in walking speed during a 400-m test and performance on a battery of short-duration mobility tasks (Short Physical Performance Battery (SPPB)). Physical activity significantly improved the adjusted walking speed of ACEi users (P < .001) but did not of nonusers. PA improved the adjusted SPPB score of ACEi users (P < .001) and of persons who used other antihypertensive drugs (P = .005) but not of antihypertensive nonusers (P = .91).The percentage of ACEi users deriving clinically significant benefit from exercise training for walking speed (30%) and SPPB score (48%) was dramatically higher than for nonusers (14% and 12%, respectively). For older adults at risk for disability, exercise-derived improvements in physical function were greater for ACEi users than users of other antihypertensive drugs and antihypertensive nonusers.

Gait Recognition Across Various Walking Speeds Using Higher Order Shape Configuration Based on a Differential Composition Model

Gait has been known as an effective biometric feature to identify a person at a distance. However, variation of walking speeds may lead to significant changes to human walking patterns. It causes many difficulties for gait recognition. A comprehensive analysis has been carried out in this paper to identify such effects. Based on the analysis, Procrustes shape analysis is adopted for gait signature description and relevant similarity measurement. To tackle the challenges raised by speed change, this paper proposes a higher order shape configuration for gait shape description, which deliberately conserves discriminative information in the gait signatures and is still able to tolerate the varying walking speed. Instead of simply measuring the similarity between two gaits by treating them as two unified objects, a differential composition model (DCM) is constructed. The DCM differentiates the different effects caused by walking speed changes on various human body parts. In the meantime, it also balances well the different discriminabilities of each body part on the overall gait similarity measurements. In this model, the Fisher discriminant ratio is adopted to calculate weights for each body part. Comprehensive experiments based on widely adopted gait databases demonstrate that our proposed method is efficient for cross-speed gait recognition and outperforms other state-of-the-art methods.

Fat Mass Loss Predicts Gain in Physical Function With Intentional Weight Loss in Older Adults

Clinical recommendation of weight loss (WL) in older adults remains controversial, partially due to concerns regarding lean mass loss and potential loss of physical function. The purpose of this study is to determine the independent associations between changes in fat and lean mass and changes in physical function in older, overweight, and obese adults undergoing intentional WL. Data from three randomized-controlled trials of intentional WL in older adults with similar functional outcomes (short physical performance battery and Pepper assessment tool for disability) were combined. Analyses of covariance models were used to investigate relationships between changes in weight, fat, and lean mass (acquired using dual-energy x-ray absorptiometry) and changes in physical function. Overall loss of body weight was -7.8 ± 6.1 kg (-5.6 ± 4.1 kg and -2.7 ± 2.4 kg of fat and lean mass, respectively). In all studies combined, after adjustment for age, sex, and height, overall WL was associated with significant improvements in self-reported mobility disability (p < .01) and walking speed (p < .01). Models including change in both fat and lean mass as independent variables found only the change in fat mass to significantly predict change in mobility disability (β[fat] = 0.04; p < .01) and walking speed (β[fat] = -0.01; p < .01). Results from this study demonstrate that loss of body weight, following intentional WL, is associated with significant improvement in self-reported mobility disability and walking speed in overweight and obese older adults. Importantly, fat mass loss was found to be a more significant predictor of change in physical function than lean mass loss.

Meaningful Change in Walking Speed

Evidence-based practitioners need to consider the sensitivity to change or “responsiveness” of outcome measures such as walking speed. The responsiveness of an outcome measure refers to its ability to accurately detect a change or difference when it has occurred. In this review, we first describe distribution-based and anchor-based methods and the most commonly reported indexes of responsiveness (ie, effect size, standard error of the measurement, minimal detectable change, standardized response mean, and minimal clinically important difference) for walking speed. We then summarize and synthesize the recent literature on the responsiveness of walking speed in different populations of older adults, patients with neurologic conditions (ie, stroke, Parkinson's disease, and Alzheimer's disease), and patients with orthopedic conditions (ie, hip fracture and knee osteoarthritis). In all of the studies cited, walking speed was sensitive to change over time and, when looking across studies, there is considerable agreement that meaningful change in walking speed is approximately 0.1 m/s.

A massage therapy on pain relief for knee osteoarthritis: A systematic review and meta-analysis

s / Osteoarthritis and Cartilage 20 (2012) S54–S296 S281 anyexercise interventionwitha shamornon-interventioncontrol inpatients with knee OA. Trialswere included if patient-reported outcome on disability and at least one of the four predefined outcomes on physical capacity were reported; 1. range of motion in the knee joint, 2. walking speed, 3. muscle strength in leg extensors and 4. aerobic capacity (VO2max). Standardized mean differences (SMD) on disability and physical capacity were estimated from differences in mean changes between intervention and control group, divided by the pooled within-group standard deviation. Only physical capacity measures used in at least 5 trials were analyzed. Meta-regression analyses were performed to examine the relationship between SMD in disability and the SMDmeasures on physical capacity. Results: Twenty seven randomized trials comparing 33 exercise interventionswith controlswere included in the analyses. Themost frequently used objective outcomes on physical capacity weremuscle strength andwalking speed, used in 24 and 19 exercise therapy interventions, respectively. Range ofmotion and VO2maxwere only used in 3 and 2 interventions respectively and was not analyzed further. There was a statistically significant relationship between change in walking speed and self-reported disability (slope1.29 [95%CI: 0.66; 1.92]; P 0.05 en (600mg/day x 3wks) 3 VAS (0-10) Y0.01 (-0.47, 0.45) >0.05 nd (10 mins/8 sessions) 4 WOMAC Y 0.05 t 8 WOMAC Y-16.6 (-7.0, -25.2) <0.001 anual therapy (6 sessions) 2 VAS(0-10) Y1.0 ND cannot be calculated from published data, ND1⁄4 No data. N1⁄4 number of included; ster Universities Osteoarthritis Index;; VAS1⁄4Visual Analogue Scale

Speeding up or slowing down?: Gait adaptations to preserve gait stability in response to balance perturbations

It has frequently been proposed that lowering walking speed is a strategy to enhance gait stability and to decrease the probability of falling. However, previous studies have not been able to establish a clear relation between walking speed and gait stability. We investigated whether people do indeed lower walking speed when gait stability is challenged, and whether this reduces the probability of falling.Nine healthy subjects walked on the Computer Assisted Rehabilitation ENvironment (CAREN) system, while quasi-random medio-lateral translations of the walking surface were imposed at four different intensities. A self-paced treadmill setting allowed subjects to regulate their walking speed throughout the trials. Walking speed, step length, step frequency, step width, local dynamic stability (LDS), and margins of stability (MoS) were measured.Subjects did not change walking speed in response to the balance perturbations (p=0.118), but made shorter, faster, and wider steps (p<0.01) with increasing perturbation intensity. Subjects became locally less stable in response to the perturbations (p<0.01), but increased their MoS in medio-lateral (p<0.01) and backward (p<0.01) direction.In conclusion, not a lower walking speed, but a combination of decreased step length and increased step frequency and step width seems to be the strategy of choice to cope with medio-lateral balance perturbations, which increases MoS and thus decreases the risk of falling.