Ground reaction forces during gait in pregnant fallers and non-fallers

Pregnant women are at a high risk of experiencing a fall. To our knowledge, ground reaction forces (GRFs) in pregnant fallers and non-fallers have not been reported.

Purpose

The purpose of this study was to examine the effects of pregnancy and fall history on GRFs during walking.

Methods

Forty one pregnant subjects in the mid 2nd and 3rd trimesters (pregnant fallers: n = 15, pregnant non-fallers: n = 14), and 40 control women walked at a freely chosen walking speed along an 8 m walkway. A force plate, hidden in the walkway, was used to collect GRFs (1080 Hz). Kinematic data (120 Hz) were collected from a marker placed on the lumbar spine to estimate walking velocity. GRF variables included mediolateral Center of Pressure (COP) excursion, and GRFs normalized to body mass. A two factor ANOVA (trimester x fall group) was used to compare subject demographics, and walking velocity (α = 0.05). A two factor ANCOVA (trimester × fall group, covariate: velocity) was performed to examine other GRF variables (Bonferroni corrected α = 0.006) and the mediolateral COP excursion (α = 0.05).

Results

Walking velocity was greater in the control group (p < 0.05). No differences were seen in the GRFs or COP movement between trimesters or between pregnant fallers and non-fallers.

Conclusions

When walking velocity was considered in the statistical model, ground reaction forces are essentially unchanged by pregnancy.     

Surface movement errors in shank kinematics and knee kinetics during gait

The movement of surface mounted targets (SMT) on a shell at the mid-shank and of bone mounted targets attached to the distal shank using a Percutaneous Skeletal Tracker (PST) were simultaneously measured during free-speed walking of three adult subjects having different body types. Surface movement errors in shank kinematic estimates were determined by expressing the segmental motion derived from the SMT relative to the PST-based segment coordinate system (SCS) located at the segment center of gravity. The greatest errors were along and around the shank longitudinal axis, with peak magnitudes of 10 mm of translation and 8° of rotation in one subject. Estimates of knee joint center locations differed by less than 11 mm in each SCS direction. Differences in estimates of net knee joint forces and moments were most prominent during stance phase, with magnitudes up to 39 N in the shank mediolateral direction and 9 N.m about the mediolateral axis. The differences in kinetics were primarily related to the effect of segment position and orientation on the expression of joint forces and on the magnitude and expression of joint moments.     

Changes in 6DOF knee kinematics during gait with decreasing gait speed

BackgroundGait speed is recognized to correlate to knee kinematic alterations. Clinically, patients with knee diseases tend to walk slowly compared to healthy controls. Hence, gait speed may serve as a confounding factor in the kinematic characteristics of patients during gait compared to healthy controls.Research questionWhether and how gait speed affects six degrees of freedom (6DOF) knee kinematics remains unclear. The current study was designed to explore whether and how decreased gait speeds affect 6DOF knee kinematics.MethodsThirty subjects (15 males and 15 females) were recruited for this study. A three-dimensional gait analysis system was used to assess the 6DOF knee kinematics of subjects at gait speeds of 4.0 km/h, 3.5 km/h, 3.0 km/h, 2.5 km/h, 2.0 km/h, 1.5 km/h, and 1.0 km/h. Kinematics of gait cycle (GC) were assessed at all gait speed levels.ResultsDecreased adduction angle (0.5–3.2 °, p < 0.05), increased external rotation (0.6–3.3 °, p < 0.05) and decreased flexion angle (1.5–17.4 °, p < 0.05) were found during most GC as gait speed level decreased. Greater anterior tibial translation (0.9−2.6 mm, p < 0.05), greater proximal translation (0.4–2.4 mm, p < 0.05) and decreased lateral tibial translation (0.5–3.0 mm, p < 0.05) were found during most GC as gait speed level decreased. Gender was also found to have great effects on 6DOF knee kinematics (p < 0.05). Interactions between gender and gait speed were also found (p < 0.05).SignificanceOur findings suggest that additional attention should be paid when dealing with kinematic comparisons of GC between controls and patients with significantly different gait speeds or genders than controls. Kinematic alterations induced by gait speed may raise concern for patients with knee diseases who struggle to walk faster than their normal speed. This may enhance our knowledge of the relationship between gait speed and 6DOF knee kinematics.     

The influence of different force and pressure measuring transducers on lower extremity kinematics measured during walking

The examination of synchronous three dimensional (3-D) kinetics and kinematics of walking in laboratory based analyses typically requires participants/patients to make foot contact with a force or pressure measuring device. However, it has been proposed that this may lead to targeting whereby participants modify their natural gait pattern in order to ensure contact with the device. This study aimed to determine the extent to which an embedded force plate (EFP) and two different pressure mats (PMs) affect natural gait kinematics. Male participants (n = 12, age 24.23 SD 4.22 years, height 1.74 m SD 0.10, mass 75.78 SD 6.90 kg) walked at a velocity of 1.25 m s⁻¹ along a 22 m walkway in four different conditions. (1) EFP, (2) FootScan (FS) PM, (3) MatScan (MS) PM, (4) no device (ND). 3-D angular kinematic parameters were collected using an eight camera motion analysis system. Differences in kinematics were examined using repeated measures ANOVAs. Significant differences were observed in hip abduction, knee flexion/extension and knee abduction between various conditions and may warrant consideration in future research. No significant differences were reported at the ankle joint in any conditions. Comparing the PMs, no significant differences were observed, however, significant differences between the MS and the EFP and ND conditions were identified. The research supports the efficacy of collecting gait kinematics at the ankle joint and in most variables measured at the knee and hip joints.     

Three-dimensional head and trunk movement characteristics during gait in children with spastic diplegia

This study uses a recently developed trunk model to determine which head and trunk kinematic parameters differentiate children with spastic diplegia from typically developing (TD) children while walking. Differences in head and trunk parameters in relation to the severity of the motor involvement (GMFCS levels) were additionally examined. The trunk model consisted of five segments (pelvis, thorax, head, shoulder line, spine). Discrete kinematic parameters (ROM, mean position) and angular waveforms were compared between 20 children with spastic diplegia (age 9.8 years ± 2.9 years; GMFCS I: n = 10, GMFCS II: n = 10) and 20 individually age-matched TD children (9.7 years ± 3 years). A new measure for overall trunk pathology, the trunk profile score (TPS), was proposed and included in the comparative analysis. Compared to TD children, children with GMFCS II showed a significantly higher TPS and increased ROM for pelvis tilt, for thorax and head in nearly all planes, and the angle of kyphosis. In children with GMFCS I, only ROM of thorax lateral bending was significantly increased. Sagittal ROM differentiated best between GMFCS levels, with higher ROM found in children with GMFCS II. Current results provide new insights into head and trunk kinematics during gait in children with spastic diplegia.     

Correlations between joint kinematics and dynamic balance control during gait in pregnancy

BackgroundDynamic balance control degrades during pregnancy, but it is not yet understood why. Mechanical aspects of the body should directly affect walking balance control, but we have recently published papers indicating that weight gains during pregnancy explain very little dynamic balance changes. Our goal was to determine if lower extremity joint kinematic changes are an indicator of walking balance control. This information is vital to understanding the route by which pregnancy increases fall risk.MethodsTwenty-three pregnant women were tested at five different times in the 2nd and 3rd trimesters of pregnancy. Participants performed walking trials at a self-selected pace. Motion capture was used to measure joint kinematics (discrete and coordination variables) and body center of mass motion. Changes over time were statistically analyzed. Correlations between kinematics and walking balance were modelled with hierarchical multiple regression models.ResultsAs pregnancy progresses, it appears that a more flexed hip posture could be driving lower extremity kinematic changes toward increased coordination between joints and increased knee and ankle motions. Walking balance changes were also detected through increased COM motion (lateral range of motion and velocity) in the lateral directions. However, there was little correlation between kinematic and balance changes (r² < 0.4). Strong correlations were only observed when all kinematics (including those that don’t ubiquitously change during pregnancy) were used in the regression model (r² > 0.7).SignificanceOur findings suggest that walking balance control is not altered by a common kinematic change between all pregnant women. While increased lateral center of mass motion should be expected with pregnancy, the kinematics leading to this increase may be person-specific. The cause of dynamic imbalance in each pregnant women (physiological, mechanical, and neurocognitive) may play an important role in determining the kinematic means by which lateral center of mass motion increases.     

The effect of intracortical bone pin application on kinetics and tibiocalcaneal kinematics of walking gait

Bone anchored markers using intracortical bone pins are one of the few available methods for analyzing skeletal motion during human gait in-vivo without errors induced by soft tissue artifacts. However, bone anchored markers require local anesthesia and may alter the motor control and motor output during gait. The purpose of this study was to examine the effect of local anesthesia and the use of bone anchored markers on typical gait analysis variables. Five subjects were analyzed in two different gait analysis sessions. In the first session, a protocol with skin markers was used. In the second session, bone anchored markers were added after local anesthesia was applied. For both sessions, three dimensional infrared kinematics of the calcaneus and tibia segments, ground reaction forces, and plantar pressure data were collected. 95% confidence intervals and boxplots were used to compare protocols and assess the data distribution and data variability for each subject. Although considerable variation was found between subjects, within-subject comparison of the two protocols revealed non-systematic effects on the target variables. Two of the five subjects walked at reduced gait speed during the bone pin session, which explained the between-session differences found in kinetic and kinematic variables. The remaining three subjects did not systematically alter their gait pattern between the two sessions. Results support the hypothesis that local anesthesia and the presence of bone pins still allow a valid gait pattern to be analyzed.     

The influence of different pelvic technical marker sets upon hip kinematics during gait

BackgroundThe pelvis is commonly tracked during three-dimensional motion analysis using markers located on the anterior and posterior superior iliac spines. However, these markers are prone to soft tissue artefact and marker occlusion, highlighting the need for alternative technical marker sets.Research questionHow comparable are hip joint kinematics calculated using two alternative pelvic technical marker sets and a conventionally modelled pelvis?MethodsFourteen participants undertook 3D gait analysis, walking overground at a self-selected pace (1.38 ± 0.14 m·s⁻¹), barefoot. Hip joint kinematics were compared using root mean square error (RMSE) between a conventionally tracked pelvis and two alternative technical marker sets; (1) posterior cluster and (2) additional iliac crest markers.ResultsThe average RMSE in the sagittal, frontal and transverse planes was 2.5° ± 2.8°, 1.6° ± 0.4° and 0.8° ± 0.4°, respectively for the posterior cluster, and 1.3° ± 0.7°, 0.8° ± 0.3° and 1.4° ± 0.5° for the iliac crest marker set. The RMSE was significantly larger for the posterior cluster compared to the iliac crest model in the sagittal (p = .05, d = .28) and frontal planes (p < .001, d = 7.65). In contrast, the RMSE was significantly lower for the posterior cluster in the transverse plane (p = .01, d = -2.85).SignificanceThe findings of this study suggest that either a posterior cluster or additional iliac crest markers offer means of accurately calculating hip joint kinematics within 3° of the conventional pelvic model. Therefore, either technical marker set offers a viable alternative to the conventional pelvic model for calculating hip joint kinematics.     

Effect of altered sagittal-plane knee kinematics on loading during the early stance phase of gait

BackgroundIndividuals with knee osteoarthritis (OA) show various dynamic sagittal-plane changes during the early stance phase of gait. However, the effect of these kinematic alterations on knee load during the early stance remains poorly understood. Research question: The purpose of this study was to examine the effect of altered sagittal- plane knee kinematics on knee load during the early stance.MethodsA total of 13 healthy adult men underwent gait analysis trials using four conditions (baseline and three altered conditions). The three altered conditions were defined as follows:1) Less flexion (LF): a gait that decreased knee flexion excursion (KFE) owing to a reduced peak knee flexion angle compared to baseline.2) Initial flexion (IF): a gait with decreased KFE owing to an increased knee flexion angle at initial contact, during which the peak knee flexion angle did not differ from baseline.3) Flexion gait (FG): a gait that increased the knee flexion angle at initial contact but did not reduce KFE compared with the baseline.Data analyzed included peak external knee flexion moment (KFM), KFM impulse (impulse was an integral value from initial contact to peak value), peak vertical ground reaction force (VGRF), and maximum loading rate.ResultsBoth LF and IF conditions significantly decreased peak VGRF (p < 0.05) compared with the baseline. Peak KFM decreased in the LF condition and increased in the FG condition versus baseline (p < 0.05). A significantly increased KFM impulse was found in both IF and FG conditions when compared with baseline (p < 0.05).SignificanceAn increase in knee flexion angle during early stance increased knee loading. Interventions are likely required for improving excessive knee flexion during early stance phase of gait in individuals with knee OA.     

Spatio-temporal parameters and lower-limb kinematics of turning gait in typically developing children

Turning is a requirement for most locomotor tasks; however, knowledge of the biomechanical requirements of successful turning is limited. Therefore, the aims of this study were to investigate the spatio-temporal and lower-limb kinematics of 90° turning. Seventeen typically developing children, fitted with full body and multi-segment foot marker sets, having performed both step (outside leg) and spin (inside leg) turning strategies at self-selected velocity, were included in the study. Three turning phases were identified: approach, turn, and depart. Stride velocity and stride length were reduced for both turning strategies for all turning phases (p < 0.03 and p < 0.01, respectively), while stance time and stride width were increased during only select phases (p < 0.05 and p < 0.01, respectively) for both turn conditions compared to straight gait. Many spatio-temporal differences between turn conditions and phases were also found (p < 0.03). Lower-limb kinematics revealed numerous significant differences mainly in the coronal and transverse planes for the hip, knee, ankle, midfoot, and hallux between conditions (p < 0.05). The findings summarized in this study help explain how typically developing children successfully execute turns and provide greater insight into the biomechanics of turning. This knowledge may be applied to a clinical setting to help improve the management of gait disorders in pathological populations, such as children with cerebral palsy.     

Weight loss changed gait kinematics in individuals with obesity and knee pain

BackgroundObesity is a mechanical risk factor for osteoarthritis. In individuals with obesity, knee joint pain is prevalent. Weight loss reduces joint loads, and therefore potentially delays disease progression; however, how the knee joint responds to weight loss in individuals with obesity and knee pain is not clear.Research questionTo assess the effect of weight loss on knee joint kinematics during gait in individuals with obesity and knee pain.MethodsWe recruited individuals with obesity (BMI ≥ 35) and knee pain who were participating in a weight loss program which included bariatric surgery or medical management. At baseline and 1 year follow-up, participants walked on a treadmill, and their knee joint kinematics were assessed using a dual-fluoroscopic imaging system and subject-specific magnetic resonance imaging knee joint models. Gait changes were represented by change in range of tibiofemoral motion, i.e., excursions in flexion-extension, adduction-abduction, internal-external rotation, anterior-posterior translation, medial-lateral translation, and superior-inferior translation during gait.ResultsTwelve individuals with obesity and knee pain completed the gait analysis at baseline and 1 year follow-up. Participants lost on average 10.4% (standard deviation: 17.2%) of their baseline body weight. Reduction in body weight was associated with increased range of flexion-extension (r = -0.75, p < 0.01) and decreased range of adduction-abduction (r = 0.60, p = 0.04) during gait. The reduction in body weight was also associated with self-reported pain decrease (r = 0.62, p = 0.04); however, the change in pain was not significantly associated with kinematic changes.SignificanceWeight loss was associated with improved gait kinematics in the sagittal and frontal planes. The change in gait pattern in individuals with obesity and knee pain was not associated with the change in pain given a reduction in body weight.     

Side to side kinematic gait differences within patients and spatiotemporal and kinematic gait differences between patients with severe knee osteoarthritis and controls measured with inertial sensors

BackgroundKinematic changes associated with knee osteoarthritis (OA) have been traditionally measured with camera-based gait analysis. Lately, inertial sensors have become popular for gait analysis with the advantage of being less time consuming and not requiring a dedicated laboratory.Research questionDo spatiotemporal and discrete kinematic gait parameters measured with the inertial sensor system RehaGait® differ between the affected and unaffected side in patients with unilateral knee OA and between patients with severe knee OA and asymptomatic control subjects? Do these differences have a similar magnitude as those reported in the literature?MethodsTwenty-two patients with unilateral knee OA scheduled for total knee replacement and 46 age matched control subjects were included in this study. Spatiotemporal parameters and sagittal kinematics at the hip, knee, and ankle joint were measured using the RehaGait® system while walking at a self-selected speed for a distance of 20 m and compared between groups.ResultsPatients with knee OA had slower walking speed, longer stride duration, shorter stride length and lower cadence (P < 0.001). Peak knee flexion during stance and swing was lower in the affected than the unaffected leg (-4.8° and -6.1°; P < 0.01). Peak knee flexion during stance and swing (-5.2° and -8.8°; P < 0.01) and knee range of motion during loading response and swing (-3.6° and -4.4°; P < 0.01) were lower than in the control group.SignificanceThese side to side differences within patients and differences between patients with knee OA and control subjects agree with known gait alterations measured with camera-based systems. The RehaGait® inertial sensor system can detect gait alterations in patients with knee OA and is suitable for gait analysis in a clinical environment.     

Old adult fallers display reduced flexibility of arm and trunk movements when challenged with different walking speeds

Specific patterns of pelvic and thorax motions are required to maintain stability during walking. This cross-sectional study explored older-adults’ gait kinematics and their kinematic adaptations to different walking speeds, with the purpose of identifying mechanisms that might be related to increased risk for falls. Fifty-eight older adults from self-care residential facilities walked on a treadmill, whose velocity was systematically increased with increments of 0.1 meters/second (m/s) from 0.5 to 0.9 m/s, and then similarly decreased. Thorax, pelvis, trunk, arms, and legs angular total range of motion (tROM), stride time, stride length, and step width were measured. Twenty-one of the subjects reported falling, and 37 didn’t fall. No significant effect of a fall history was found for any of the dependent variables. A marginally significant interaction effect of fall history and walking speed was found for arms’ tROM (p = 0.098). Speed had an effect on many of the measures for both groups. As the treadmill’s velocity increased, the non-fallers increased their arm (15.9 ± 8.6° to 26.6 ± 12.7°) and trunk rotations (4.7 ± 1.9° to 7.2 ± 2.8°) tROM, whereas for the fallers the change of arm (14.7 ± 14.8° to 20.8 ± 13°) and trunk (5.5 ± 2.9° to 7.3 ± 2.3°) rotations tROM were moderate between the different walking speeds. We conclude that walking speed manipulation exposed different flexibility trends. Only non-fallers demonstrated the ability to adapt trunk and arm ROM to treadmill speed i.e., had a more flexible pattern of behavior for arm and trunk motions, supporting the upper-body’s importance for stability while walking.     

Wearable inertial sensors to measure gait and posture characteristic differences in older adult fallers and non-fallers: A scoping review

BackgroundWearable inertial sensors have grown in popularity as a means of objectively assessing fall risk. This review aimed to identify gait and posture differences among older adult fallers and non-fallers which can be measured with the use of wearable inertial sensors. In addition to describing the number of sensors used to obtain measures, the concurrent anatomical locations, how these measures compare to current forms of clinical fall risk assessment tests and the setting of tests.MethodsFollowing the development of a rigorous search strategy, MEDLINE, Web of Science, Cochrane, EMBASE, PEDro, and CINAHL were systematically searched for studies involving the use of wearable inertial sensors, to determine gait and postural based differences among fallers or those at high fall risk compared with non-fallers and low fall risk adults aged 60 years and older.ResultsThirty five papers met the inclusion criteria. One hundred and forty nine gait and posture characteristic differences were identified using wearable inertial sensors. There were sensor derived measures which significantly and strongly correlated with traditional clinical tests. The use of a single wearable inertial sensor located at the lower posterior trunk, was most the most effective location and enough to ascertain multiple pertinent fall risk factors.ConclusionThis review identified the capabilities of identifying fall risk factors among older adults with the use of wearable inertial sensors. The lightweight portable nature makes inertial sensors an effective tool to be implemented into clinical fall risk assessment and continuous unsupervised home monitoring, in addition to, outdoor testing.     

Measuring gait kinematics in patients with severe hip osteoarthritis using wearable sensors

BackgroundThe popularity of inertial sensors in gait analysis is steadily rising. To date, an application of a wearable inertial sensor system for assessing gait in hip osteoarthritis (OA) has not been reported.Research question: Can the known kinematic differences between patients with hip OA and asymptomatic control subjects be measured using the inertial sensor system RehaGait®?MethodsThe patients group consisted of 22 patients with unilateral hip OA scheduled for total hip replacement. Forty-five age matched healthy control subjects served as control group. All subjects walked for a distance of 20 m at their self-selected speed. Spatiotemporal parameters and sagittal kinematics at the hip, knee, and ankle including range of motion (ROM) were measured using the RehaGait® system.ResultsPatients with hip OA walked at a slower walking speed (−0.18 m/s, P < 0.001) and with shorter stride length (−0.16 m, P < 0.001), smaller hip ROM during stance (−11.6°, P < 0.001) and swing (−11.3°, P < 0.001) and smaller knee ROM during terminal stance and swing (−9.0° and−11.5°, P < 0.001). Patients had a smaller hip ROM during stance and swing and smaller knee ROM during terminal stance and swing in the affected compared to the unaffected side (P < 0.001).SignificanceThe differences in spatiotemporal and kinematic gait parameters between patients with hip OA and age matched control subjects assessed using the inertial sensor system agree with those documented for camera-based systems. Hence, the RehaGait® system can measure gait kinematics characteristic for hip OA, and its use in daily clinical practice is feasible.     

Knee kinematics and kinetics during gait, step and hop in males with a 16 years old ACL injury compared with matched controls

The objective of this study was to compare subjects who sustained an ACL injury during soccer 16 years ago with a control group with regard to knee kinematics and kinetics of gait, step activity and cross over hop. Secondly, in the injured subjects, the purpose was to study the impact on kinematics and kinetics of characteristics such as operative status, meniscal resection, being symptomatic, having knee extensor weakness and of having radiographic knee OA. Data from a 3-dimensional gait analysis system (VICON) were used to calculate kinetics and kinematics during gait, step activity and cross over hop of 12 male subjects who had an anterior cruciate ligament injury 16 years earlier. Twelve uninjured subjects matched for age, sex, BMI and activity level served as controls. No significant differences in knee kinematics and kinetics between the ACL group and the control group were found. The variability of some parameters of step and all parameters of hop activity was generally larger in the ACL injured subjects compared with the controls. The ACL injured subjects had a significantly worse clinical status compared with the controls. Reduced knee extension strength was associated with joint moment reductions especially during step activity and cross over hop. Despite a significantly worse clinical status, as determined by self-report and isokinetic strength testing, no significant differences were seen in knee joint kinetics and kinematics in an ACL injured group 16 years after injury compared with a matched control group. The variation was larger among the ACL injured subjects indicating the need for larger study groups in gait and movement analysis in long-term follow-up of ACL injury.     

Test of two prediction methods for minimum and maximum values of gait kinematics and kinetics data over a range of speeds

BackgroundMinimum and maximum values of gait kinematics and kinetics data are commonly used to quantitatively describe a walking pattern.Research questionThe purposes of this study were to determine the effect of speed on the minimum and maximum values of gait kinematics and kinetics variables and to test two prediction methods for the estimation of these minimum and maximum values at different gait speeds.MethodsAn open dataset with the data of 24 healthy adults (age: 27.6 ± 4.4 years, height: 171.1 ± 10.5 cm, body mass: 68.4 ± 12.2 kg) walking on a treadmill at eight gait speeds was employed in this study. The minimum and maximum angles and moments of the hip, knee, and ankle joints were extracted from speed-dependent prediction curves solely for the minimum and maximum values (PEAK method) and from speed-dependent prediction curves for the entire gait cycle (CYCLE method). The overall error, computed as the root-mean-square error (RMSE), for the minimum and maximum values predicted by these two methods were compared with the experimental true values.ResultsThe RMSEs for the joint angles were PEAK: 3.86 ± 1.21°, CYCLE: 3.88 ± 1.18° and for the joint moments were PEAK: 0.129 ± 0.052 Nm/kg, CYCLE: 0.131 ± 0.052 Nm/kg.SignificanceThe two prediction methods tested can be used to estimate the minimum and maximum values of biomechanical gait variables at a certain speed.     

Head and trunk stabilization strategies during forward and backward walking in healthy adults

The purpose of this study was to investigate the head and trunk equilibrium strategies while walking forwards and backwards under different conditions (eyes open vs. closed, hard vs. soft surface) in a sample of 11 consenting healthy adult subjects. Nine markers placed on the subject allowed us to record the kinematics of the head, spine and pelvis segments while walking. The data were acquired and analyzed using an optical TV-image processor (ELITE system). For each locomotor trial, the walking speed as well as the absolute angular dispersions and the anchoring indexes (AI) of six segments around the roll and pitch axes were calculated to assess the head and trunk equilibrium strategies. A three-way repeated measures analysis of variance was used to depict differences between the walking conditions. The results showed that the walking speed was affected by the locomotion tasks (P<0.05) with values ranging from 1.10±0.21 m s⁻¹ for natural conditions (walking forwards on a hard surface, eyes open) to 0.79±0.15 m s⁻¹ for the most unusual conditions (walking backwards on a foam support, eyes closed). In general, walking backwards reduced the angular dispersion of the spine segments while the absolute angular dispersions of the head and pelvis did not vary significantly with any factors (P>0.05). The AI around the roll axis indicated good stabilization in space of the head and pelvis with high positive values and this stability increased while the subject was walking backwards on a soft surface (foam). By contrast, the spinal segments were predominantly stabilized on the underlying segment (negative AI), and this stabilization even increased when the subjects walked backwards on a soft surface. Increasing the locomotion difficulty thus induced a generally rigid (‘en bloc’) functioning of the spinal segments and increased effectiveness of the head and pelvis stabilization strategies in space, especially when walking backwards on a soft surface.     

Recovery in functional non-copers following anterior cruciate ligament rupture as detected by gait kinematics

ObjectivesTo evaluate if gait compensation strategies for selected kinematic variables can be identified in anterior cruciate ligament (ACL) deficient non-copers using two-dimensional (2D) clinical gait analysis.DesignProspective observational design, repeated measures.SettingUniversity hospital, out-patients department.PatientsSixty-three patients that attended the acute knee screening service were diagnosed with an acute ACL rupture and consented to participate. A sub-set of 15 copers/adapters and 13 non-copers were eligible for final analysis because they were contactable for sub-classification and had gait analysis at 1 and 4 months post-injury.Main outcome measures2D video gait analysis for sagittal plane hip, knee and ankle kinematics and time–distance variables.ResultsAt 4 months post-injury non-copers demonstrated significantly less recovery of knee angle (F_(1,1)=5.79, p<0.024), hip displacement angle (F_(1,1)=4.89, p<0.036), step length (F_(1,1) =6.80, p=0.015), cadence (F_(1,1)=5.85, p=0.023) and velocity (F_(1,1)=10.89, p=0.003), compared to copers/adapters. Also non-copers demonstrated altered correlations between gait parameters.ConclusionAt 4 months post-injury non-copers had an inferior gait performance compared to copers/adapters for kinematics and time–distance variables. 2D clinical kinematic gait analysis, particularly of the hip and knee can inform early rehabilitation techniques and monitor recovery.