Differences In Gait Patterns Research Articles

Custom sizing of lower limb exoskeleton actuators using gait dynamic modelling of children with cerebral palsy

The use of exoskeletons as an aid for people with musculoskeletal disorder is the subject to an increasing interest in the research community. These devices are expected to meet the specific needs of users, such as children with cerebral palsy (CP) who are considered a significant population in pediatric rehabilitation. Although these exoskeletons should be designed to ease the movement of people with physical shortcoming, their design is generally based on data obtained from healthy adults, which leads to oversized components that are inadequate to the targeted users. Consequently, the objective of this study is to custom-size the lower limb exoskeleton actuators based on dynamic modeling of the human body for children with CP on the basis of hip, knee, and ankle joint kinematics and dynamics of human body during gait. For this purpose, a multibody modeling of the human body of 3 typically developed children (TD) and 3 children with CP is used. The results show significant differences in gait patterns especially in knee and ankle with respectively 0.39 and −0.33 (Nm/kg) maximum torque differences between TD children and children with CP. This study provides the recommendations to support the design of actuators to normalize the movement of children with CP.

Intra-individual gait pattern variability in specific situations: Implications for forensic gait analysis

In this study, inter- and intra-individual gait pattern differences are examined in various gait situations by means of phase diagrams of the extremity angles (cyclograms). 8 test subjects walked along a walking distance of 6m under different conditions three times each: barefoot, wearing sneakers, wearing combat boots, after muscular fatigue, and wearing a full-face motorcycle helmet restricting vision. The joint angles of foot, knee, and hip were recorded in the sagittal plane. The coupling of movements was represented by time-adjusted cyclograms, and the inter- and intra-individual differences were captured by calculating the similarity between different gait patterns. Gait pattern variability was often greater between the defined test situations than between the individual test subjects. The results have been interpreted considering neurophysiological regulation mechanisms. Footwear, masking, and fatigue were interpreted as disturbance parameters, each being a cause for gait pattern variability and complicating the inference of identity of persons in video recordings.

Age-independent and age-dependent sex differences in gait pattern determined by principal component analysis

Although various studies have reported significant sex differences in pelvic and/or hip-joint motion during normal walking in healthy adults, it is still unclear whether such differences are among the most dominant age-independent sex differences. This study was conducted to analyze the whole waveform of lower-extremity joint kinematics obtained from 191 healthy adults using a principal component analysis (PCA). The PCA was conducted using a 955×1212 input matrix constructed from the participants’ time-normalized pelvic and right-lower-limb-joint angles along three axes (five trials of 191 participants×101 data points×4 angles×3 axes). Two-way (age×sex) analyses of variance were conducted on the principal component scores (PCSs) of principal component vectors (PCVs) 1 through 6, each of which explained more than 5% of the variance. We identified a PCV that exhibits a significant age–sex interaction (PCV 1). The characteristics of sex differences reported in previous studies could be observed in the reconstructed waveforms of this PCV. Thus, we can conclude that the sex differences in the gaits reported in previous studies are not consistent across age groups. Furthermore, we also found a PCV that exhibited only a significant sex difference (PCV 6). This PCV was the first and only PCV to exhibit a sex difference without any age-related effect or age–sex interaction. Therefore, we concluded that the movement related to this PCV is age-independent and is the most dominant sex difference in the gaits observed during normal walking.

No Differences Identified in Transverse Plane Biomechanics Between Medial Pivot and Rotating Platform Total Knee Implant Designs

BackgroundTotal knee arthroplasties (TKAs) using well-designed, fixed bearing prostheses, such as medial pivot (MP), have produced good long-term results. Rotating-platform, posterior-stabilized (RP-PS) mobile bearing implants were designed to decrease polyethylene wear. Sagittal and coronal plane TKA biomechanics are well examined and correlated to polyethylene wear. However, limited research findings describe this relationship in transverse plane. We assumed that although axial plane biomechanics might not be the most destructive parameters on polyethylene wear, it is important to clarify their role because both joint kinematics and kinetics in all 3 planes are important input parameters for TKA wear testing (International Organization for Standardization 14243-1 and 14343-3). Our hypothesis was that transverse plane overall range of motion (ROM) and/or peak moment show differences that reflect on wear advantages when compared RP-PS implants to MP designs. MethodsTwo groups (MPs = 24 and RP-PSs = 22 subjects) were examined by using 3D gait analysis. The variables were total internal-external rotation (IER) ROM and peak IER moments. ResultsNo statistically significant difference was demonstrated between the 2 groups in kinetics (P = .389) or kinematics (P = .275). ConclusionIn the present study, no wear advantages were found between 2 TKAs. Both designs showed identical kinetics at the transverse plane in level-ground walking. Kinematic analysis could not illustrate any statistically significant difference in terms of overall IER ROM. Nevertheless, kinematic gait pattern differences observed possibly reflect different patterns of joint surface motion or abnormal gait patterns. Thus, wear testing with various input waveforms combined with functional data analysis will be necessary to identify the actual effects of gait variability on polyethylene wear.

Gait pattern differences between different forms of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system. MS can cause different patterns of motor disturbances and gait difficulties in all its main clinical phenotypes: relapsing–remitting (RRMS), secondary-progressive (SPMS) or primary-progressive MS (PPMS). We mesasured gait pattern and characteristics in 54 MS patients, 40 with RRMS and 14 with PPMS. In those two forms we compared effects of dual task paradigm on gait characteristics (motor or mental task performance during gait) and compared gait pattern parameters (gait cycle time, stride length, single and double limb support time, as well as their coefficients of variation). Gait cycle is generally considered as automatically generated rhythmic pattern. However, tasks performed during gait in MS are affecting gait parameters differently. Cycle time is longer and stride length is shorter in RR compared to PP form, while motor and mental tasks are affecting gait parameters of both MS forms in similar manner, increasing their coefficients of variation. Changes in gait parameters and characteristics in RRMS and PPMS forms might be the consequences of different internal and external interactions. Those differences could help to design and separate treatment strategies for different MS forms.

Validation of a smartphone-based measurement tool for the quantification of level walking

IntroductionIt is important to assess and quantify gait in order to determine the severity of impairments during gait and to evaluate therapeutic interventions. However, laboratory gait assessment is expensive and time consuming and there is a lack of an easily applicable tool for the quantification of gait in clinical practice. The aim of this study was to validate a smartphone-based measurement tool for the quantification of level walking. MethodsVertical center of mass displacement and step duration of 22 healthy young adults were assessed by a smartphone application and a motion capture system. Intra-session reliability was evaluated by repeated-measures ANOVA, intraclass correlation coefficient (ICC), and standard error of measurement. In order to evaluate the concurrent validity of the smartphone application, smartphone- and motion capture-derived values were compared by Pearson correlation coefficient and Bland-Altman limits of agreement. ResultsSix out of eight variables derived by the smartphone application showed an excellent reliability (ICC≥0.75) and all variables correlated significantly with measurements of the motion capture system with moderate to strong correlations ranging from 0.61 to 0.92. ConclusionThe results showed a great potential of the smartphone application to be a user-friendly and valid tool for the assessment of gait in clinical practice. Further research needs to investigate whether the smartphone application is able to detect differences in gait patterns following therapeutic or orthopedic interventions and whether it is valid for the quantification of gait in people with movement disorders.

Factors affecting the energy cost of level running at submaximal speed.

Metabolic measurement is still the criterion for investigation of the efficiency of mechanical work and for analysis of endurance performance in running. Metabolic demand may be expressed either as the energy spent per unit distance (energy cost of running, C r) or as energy demand at a given running speed (running economy). Systematic studies showed a range of costs of about 20 % between runners. Factors affecting C r include body dimensions: body mass and leg architecture, mostly calcaneal tuberosity length, responsible for 60-80 % of the variability. Children show a higher C r than adults. Higher resting metabolism and lower leg length/stature ratio are the main putative factors responsible for the difference. Elastic energy storage and reuse also contribute to the variability of C r. The increase in C r with increasing running speed due to increase in mechanical work is blunted till 6-7 m s(-1) by the increase in vertical stiffness and the decrease in ground contact time. Fatigue induced by prolonged or intense running is associated with up to 10 % increased C r; the contribution of metabolic and biomechanical factors remains unclear. Women show a C r similar to men of similar body mass, despite differences in gait pattern. The superiority of black African runners is presumably related to their leg architecture and better elastic energy storage and reuse.

A Pilot Study on Gait Kinematics of Old Women with Bound Feet.

Foot binding has a long and influential history in China. Little is known about biomechanical changes in gait caused by bound foot. The purpose of this study was to investigate the differences in lower limb kinematics between old women with bound feet and normal feet during walking. Six old women subjects (three with bound feet and three controls with normal feet) volunteered to participate in this study. Video data were recorded with a high speed video camera and analysed in the SIMI motion analysis software. Compared to normal controls, bound feet subjects had faster gait cadence with shorter stride length as well as smaller ankle and knee range of motion (ROM). During preswing phase, ankle remained to be dorsiflexion for bound foot subjects. The data from bound foot group also demonstrated that toe vertical displacement increased continuously during whole swing phase without a minimum toe clearance (MTC). The findings indicate that older women with bound feet exhibit significant differences in gait pattern compared to those with normal feet, which is characterised by disappeared propulsion/push-off and reduced mobility of lower limb segments.

The Effects of Vibration on the Gait Pattern and Vibration Perception Threshold of Children With Idiopathic Toe Walking.

The effectiveness of idiopathic toe walking treatments is not conclusive. The study investigated the use of vibration as a therapeutic/treatment method for children with idiopathic toe walking. Fifteen children with idiopathic toe walking and 15 typically developing children, aged 4 to 10 years, completed the study. The study included a barefoot gait examination and a vibration perception threshold test before and after standing on a whole body vibration machine for 60 seconds. Temporal-spatial parameters were recorded along with HR32, a calculation designed to distinguish on aspects of the toe-walking pattern. No significant gait pattern differences were found between children with idiopathic toe walking and typically developing children after one bout of vibration intervention. HR32 was found to be a means to identify the toe-walking pattern (P < .001). Hypersensitivity to vibration of children with idiopathic toe walking was not found in the current study (P = .921).

Gait pattern differences between children with mild scoliosis and children with unilateral cerebral palsy.

This study was conducted to investigate the effects of asymmetrical body posture alone, i.e., the effects seen in children with mild scoliosis, vs. the effects of body posture control impairment, i.e., those seen in children with unilateral cerebral palsy on gait patterns. Three-dimensional instrumented gait analysis (3DGA) was conducted in 45 children with hemiplegia and 51 children with mild scoliosis. All the children were able to walk without assistance devices. A set of 35 selected spatiotemporal gait and kinematics parameters were evaluated when subjects walked on a treadmill. A cluster analysis revealed 3 different gait patterns: a scoliotic gait pattern and 2 different hemiplegic gait patterns. The results showed that the discrepancy in gait patterns was not simply a lower limb kinematic deviation in the sagittal plane, as expected. Additional altered kinematics, such as pelvic misorientation in the coronal plane in both the stance and swing phases and inadequate stance phase hip ad/abduction, which resulted from postural pattern features, were distinguished between the 3 gait patterns. Our study provides evidence for a strong correlation between postural and gait patterns in children with unilateral cerebral palsy. Information on differences in gait patterns may be used to improve the guidelines for early therapy for children with hemiplegia before abnormal gait patterns are fully established. The gait pathology characteristic of scoliotic children is a potential new direction for treating scoliosis that complements the standard posture and walking control therapy exercises with the use of biofeedback.

Novel characterization of gait impairments in people with multiple sclerosis by means of the gait profile score

The assessment of gait abnormalities in individuals with multiple sclerosis (MS) represents a key factor in evaluating the effectiveness of rehabilitation treatments. Despite the availability of sophisticated equipment to objectively evaluate the kinematic aspects of gait, there are still some difficulties in processing the large and complex amount of data they produce in the daily clinical routine. On the basis of the above-mentioned considerations we propose a novel characterization of gait kinematics in individuals with MS, based on a single measure (gait profile score, GPS) obtained from a quantitative three-dimensional analysis of gait performed using an opto-electronic system. We also investigated the correlation between GPS and the Expanded Disability Status Scale (EDSS) values. Thirty-four patients suffering from relapsing–remitting MS (13 female, 21 male, mean age 46.7years) with an EDSS score of ≤6 underwent a gait analysis from which the GPS index was calculated. Their results were compared with those of a control group of healthy age- and gender-matched subjects. The GPS of individuals with MS was found significantly higher with respect to controls (9.12° vs. 5.67°, p<0.001) as the result of kinematic differences in gait patterns referring to pelvic tilt and rotation, hip flexion–extension and rotation, knee flexion–extension and ankle dorsi- and plantar-flexion. A moderate correlation was also found between the EDSS score of the participants and their GPS values (r=0.63, p<0.001). The GPS index thus appears suitable to represent gait deviations from physiological patterns in individuals affected by MS and potentially useful in assessing the outcomes related both to rehabilitation programs and pharmacologic/physical therapies.

Gait pattern differences in children with unilateral cerebral palsy.

Children with cerebral palsy (CP) often have atypical body posture patterns and abnormal gait patterns resulting from functional strategies to compensate for primary anomalies that are directly attributable to damage to the central nervous system. Our previous study revealed two different postural patterns in children with unilateral CP: (1) a pattern with overloading of the affected body side and (2) a pattern with under-loading of the affected side. The purpose of present study was to test whether different gait patterns dependent on weight distribution between the affected and unaffected body sides could be detected in these children. The study included 45 outpatients with unilateral CP and 51 children with mild scoliosis (reference group). The examination consisted of two inter-related parts: paedobarographic measurements of the body mass distribution between the body sides and three-dimensional instrumented gait analysis. Using cluster analysis based on the Gillette Gait Index (GGI) values, three gait patterns were described: a scoliotic gait pattern and two hemiplegic gait patterns, corresponding to overloading/under-loading of the hemi-side, which are the pro-gravitational gait pattern (PGP) and the anti-gravitational gait pattern (AGP), respectively. The results of this study showed that subjects with AGP presented a higher degree of deviation from the normal gait than children with PGP. This proof that there are differences in the GGI between the AGP and PGP could be a starting point to identify kinematic differences between these gaits in a follow-up study.

The difference of gait pattern according to the state of the corticospinal tract in chronic hemiparetic stroke patients

The lateral corticospinal tract (CST) is one of the most important neuronal pathways that mediate voluntary movements in the human brain. However, little is known about the role of the lateral CST on the gait. We attempted to investigate differences in gait pattern using a motion analysis system according to the integrity of the contralateral CST, which was classified using diffusion tensor tractography (DTT) in chronic hemiparetic stroke patients. We recruited 16 chronic hemiparetic stroke patients and 12 normal subjects for this study. DTT findings of the CST for patients were classified into two groups: group A (eight patients); the integrity of the CST was preserved, group B (eight patients) - the CST was discontinued at or below the stroke lesion. We compared variables of gait between group A, group B, and normal controls using the motion analysis system. Group A and the control group showed a significantly higher peak angle for ankle dorsiflexion, knee internal rotation, and hip flexion, compared with group B (p < 0.05). On the other hand, the peak angle for ankle plantarflexion/external rotation, knee flexion/abduction, and hip extension of group A and group B were significantly lower than those of the control group (p < 0.05). We found that severe injury of the contralateral CST caused decreased movement of ankle dorsiflexion, knee internal rotation, and hip flexion in chronic hemiparetic stroke patients. As a result, the circumduction and abduction gait pattern in stroke patients is closely associated with severe injury of the contralateral CST.

A quantitative analysis of gait patterns in vestibular neuritis patients using gyroscope sensor and a continuous walking protocol.

BackgroundLocomotion involves an integration of vision, proprioception, and vestibular information. The parieto-insular vestibular cortex is known to affect the supra-spinal rhythm generators, and the vestibular system regulates anti-gravity muscle tone of the lower leg in the same side to maintain an upright posture through the extra-pyramidal track. To demonstrate the relationship between locomotion and vestibular function, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and normal subjects using a gyroscope sensor and long-way walking protocol.MethodsGyroscope sensors were attached to both shanks of healthy controls (n=10) and age-matched VN patients (n = 10). We then asked the participants to walk 88.8 m along a corridor. Through the summation of gait cycle data, we measured gait frequency (Hz), normalized angular velocity (NAV) of each axis for legs, maximum and minimum NAV, up-slope and down-slope of NAV in swing phase, stride-swing-stance time (s), and stance to stride ratio (%).ResultsThe most dominant walking frequency in the VN group was not different compared to normal control. The NAVs of z-axis (pitch motion) were significantly larger than the others (x-, y-axis) and the values in VN patients tended to decrease in both legs and the difference of NAV between both group was significant in the ipsi-lesion side in the VN group only (p=0.03). Additionally, the gait velocity of these individuals was decreased relatively to controls (1.11 ± 0.120 and 0.84 ± 0.061 m/s in control and VN group respectively, p<0.01), which seems to be related to the significantly increased stance and stride time of the ipsi-lesion side. Moreover, in the VN group, the maximum NAV of the lesion side was less, and the minimum one was higher than control group. Furthermore, the down-slope and up-slope of NAV decreased on the impaired side.ConclusionThe walking pattern of VN patients was highly phase-dependent, and NAV of pitch motion was significantly decreased in the ipsi-lesion side. The change of gait rhythm, stance and stride time, and maximum/minimum NAV of the ipsi-lesion side were characteristics of individuals with VN.

The effect of foot structure and functional foot stability on the gait patterns of the foot

Background Poor foot structure, such as flat feet or high arched feet were thought to cause excessive foot movement during gait, which in turn is the pre-cursor to foot injuries [1,3]. However, some studies claimed that the differences in gait patterns may not be due to foot structure alone [4,8,11]. It has been suggested that good foot functional stability can ‘protect’ the mal-aligned foot from injuries [9]. Functional Foot Stability is defined in this study as ‘the ability of the foot to continually adjust its position to maintain the body in an upright, balanced position’. An individual with good functional foot stability will be able to sense the foot position and if necessary, correct the position of the foot, thus preventing potential foot injuries. Whilst studies have been also done to relate foot structure and functional stability [6], as well as functional stability and gait patterns [12,14], no study has been done to investigate the combined effect of foot structure and functional foot stability on gait patterns. Therefore, this study examines the combined effect of foot structure and functional foot stability on running gait patterns.

Gait pattern in 9-11-year-old children with generalized joint hypermobility compared with controls; a cross-sectional study

BackgroundTo study differences in gait patterns in 10-year-old children with Generalized Joint Hypermobility (GJH) and with no GJH (NGJH).MethodsA total of 37 children participated (19 GJH, 18 NGJH, mean age 10.2 (SD 0.5) years). Inclusion criteria for GJH were a Beighton score of ≥5, with at least one hypermobile knee joint; for NGJH a Beighton score of ≤4, and no hypermobile knees and for both groups no knee pain during the previous week. All children were recorded by five video cameras, while they walked across three force platforms. Net joint moments were calculated in 3D by inverse dynamics and peak values provided input to statistical analyses.ResultsIn the frontal plane, children with GJH had a significantly lower peak knee abductor moment and peak hip abductor moment. In the sagittal plane, the peak knee flexor moment and the peak hip extensor moment were significantly lower in the GJH group although the absolute difference was small.ConclusionsThe walking pattern was the same for children with GJH and for healthy children, as there were no differences in kinematics, but it was, however, performed with different kinetics. Children with GJH walked with lower ankle, knee and hip joint moments compared to children with NGJH. However, the clinical importance of these differences during normal gait is unknown. To obtain this knowledge, children with GJH must be followed longitudinally.Trial registrationThe study was approved by the Committee on Biomedical Research Ethics for Copenhagen and Frederiksberg, Denmark (jnr. KF01-2006-178).

Metabolic cost and mechanics of walking in women with fibromyalgia syndrome

BackgroundFibromyalgia syndrome (FS) is characterized by the presence of widespread pain, fatigue, muscle weakness and reduced work capacity. Previous research has demonstrated that women with fibromyalgia have altered walking (gait) patterns, which may be a consequence of muscular pain. This altered gait is characterized by greater reliance on hip flexors rather than ankle plantar flexors and resembles gait patterns seen in normal individuals walking at higher speeds, suggesting that gait of individuals with fibromyalgia may be less efficient.This study compared rates of energy expenditure of 6 females with FS relative to 6 normal, age and weight matched controls, at various walking speeds on a motorized treadmill. Metabolic measurements including V02 (ml/kg/min), respirations, heart rate and calculated energy expenditures as well as the Borg Scale of Perceived Exertion scale ratings were determined at baseline and for 10 min while walking at each of 2, 4 and 5 km/hour on 1% grade. Kinematic recordings of limb and body movements while treadmill walking and separate measurements of ground reaction forces while walking over ground were also determined. In addition, all subjects completed the RAND 36-Item Health Survey (1.0).FindingsGait analysis results were similar to previous reports of altered gait patterns in FS females. Despite noticeable differences in gait patterns, no significant differences (p > 0.05) existed between the FS and control subjects on any metabolic measures at any walking speed. Total number of steps taken was also similar between groups. Ratings on the Borg Scale of Perceived Exertion, the RAND and self-reported levels of pain indicated significantly greater (p < 0.05) perceived effort and pain in FS subjects relative to control subjects during walking and daily activities.ConclusionsThe altered gait patterns and greater perceptions of effort and pain did not significantly increase the metabolic costs of walking in women with FS and hence, increased sensations of fatigue in FS women may not be related to alteration in metabolic cost of ambulation.

Self-paced versus fixed speed treadmill walking

Instrumented treadmills are increasingly used in gait research, although the imposed walking speed is suggested to affect gait performance. A feedback-controlled treadmill that allows subjects to walk at their preferred speed, i.e. functioning in a self-paced (SP) mode, might be an attractive alternative, but could disturb gait through accelerations of the belt. We compared SP with fixed speed (FS) treadmill walking, and also considered various feedback modes. Nineteen healthy subjects walked on a dual-belt instrumented treadmill. Spatio-temporal, kinematic and kinetic gait parameters were derived from both the average stride patterns and stride-to-stride variability. For 15 out of 70 parameters significant differences were found between SP and FS. These differences were smaller than 1cm, 1°, 0.2Nm and 0.2W/kg for respectively stride length and width, joint kinematics, moments and powers. Since this is well within the normal stride variability, these differences were not considered to be clinically relevant, indicating that SP walking is not notably affected by belt accelerations. The long-term components of walking speed variability increased during SP walking (43%, p<0.01), suggesting that SP allows for more natural stride variability. Differences between SP feedback modes were predominantly found in the timescales of walking speed variability, while the gait pattern was similar between modes. Overall, the lack of clinically significant differences in gait pattern suggests that SP walking is a suitable alternative to fixed speed treadmill walking in gait analysis.

A Novel Approach to Quantify Time Series Differences of Gait Data Using Attractor Attributes

In this paper we introduce a new method to expressly use live/corporeal data in quantifying differences of time series data with an underlying limit cycle attractor; and apply it using an example of gait data. Our intention is to identify gait pattern differences between diverse situations and classify them on group and individual subject levels. First we approximated the limit cycle attractors, from which three measures were calculated: δM amounts to the difference between two attractors (a measure for the differences of two movements), δD computes the difference between the two associated deviations of the state vector away from the attractor (a measure for the change in movement variation), and δF, a combination of the previous two, is an index of the change. As an application we quantified these measures for walking on a treadmill under three different conditions: normal walking, dual task walking, and walking with additional weights at the ankle. The new method was able to successfully differentiate between the three walking conditions. Day to day repeatability, studied with repeated trials approximately one week apart, indicated excellent reliability for δM (ICCave > 0.73 with no differences across days; p > 0.05) and good reliability for δD (ICCave = 0.414 to 0.610 with no differences across days; p > 0.05). Based on the ability to detect differences in varying gait conditions and the good repeatability of the measures across days, the new method is recommended as an alternative to expensive and time consuming techniques of gait classification assessment. In particular, the new method is an easy to use diagnostic tool to quantify clinical changes in neurological patients.

Gait characteristics of post-poliomyelitis patients: Standardization of quantitative data reporting

ObjectivesTo evaluate the differences in gait characteristics and gait symmetry of post-polio syndrome (PPS) patients ambulating with or without shoes and between subgroups walking with different walking aids and orthoses, study the correlation of these data with personal data, illness condition, physical health, frequency of using aids and orthotics and frequency of falls, and derive recommendations for standardization of reporting these data. MethodTwenty-six PPS subjects ambulated with their own walking devices. We calculated spatio-temporal parameters and symmetry indices (SI) of gait using a data acquired by a motion capture system. We compared inter-subject differences in gait pattern for PPS groups that differed by questionnaire-obtained data of demographics, physical activity, polio history, falls and walking aids. Additional inter-subject comparisons were performed between normal subjects (n=16), PPS patients walking with shoes with/without an ankle-foot-orthosis (n=11), PPS patients walking with knee-ankle-foot-orthosis (n=5), and PPS patients walking with a walker/crutches (n=10). We also compared intra-subject variability in PPS subjects who were able to repeat the trials barefoot. ResultsOur main results show that subjects who reported participating in physical activity twice a week or more had significantly better step time and double support symmetry. Subjects who use walking aids on a daily basis had significantly higher gait cadence and shorter stride time. Also, subjects that do not require knee-ankle-foot orthoses and/or walking aids walked with a smaller base width and better symmetry in stance and swing durations than PPS subjects who require these aids. ConclusionsThe gait pattern of PPS patients is related to numerous intrinsic and extrinsic factors. Standardization of the reporting protocol of gait-related data of PPS patients is crucial for patient evaluation and treatment design.