Trunk sway during walking among older adults: Norms and correlation with gait velocity

The aim of this study was to establish quantitative norms for trunk sway during walking for older male and female ambulatory adults at different age groups (65–70, 71–75, 76–80, ≥81). We also assessed the relationship between dynamic trunk sway and gait velocity in older individuals with clinically normal or abnormal gaits. Trunk sway in medio-lateral (roll) and antero-posterior (pitch) planes was measured using a body-mounted gyroscope (SwayStar) during walking on a 4.5 m long instrumented walkway. Of the 284 older adults (mean age 76.8, 54.6% women) in this sample, the mean ± SD value of roll and pitch angles were 6.0 ± 2.0° and 6.7 ± 2.2° respectively. Older women showed significantly greater trunk sway in both roll and pitch angles than older men (p < 0.01). In both men and women, there was no significant association of roll angle with age although gait velocity decreased with increasing age. The relationship between roll angle and gait velocity was U-shaped for the overall sample. Among the subgroup with clinically normal gait, increased roll angle was associated with increased gait velocity (p < 0.001). However, there was no significant relationship between roll angle and gait velocity among the subgroup with abnormal gait. Therefore, the relationship between medio-lateral trunk sway and gait velocity differs depending on whether gait is clinically normal.We conclude that trunk sway during walking should be interpreted with consideration of both gait velocity and presence of gait abnormality in older adults.     

Trunk sway during walking among older adults: Norms and correlation with gait velocity

The aim of this study was to establish quantitative norms for trunk sway during walking for older male and female ambulatory adults at different age groups (65–70, 71–75, 76–80, ≥81). We also assessed the relationship between dynamic trunk sway and gait velocity in older individuals with clinically normal or abnormal gaits. Trunk sway in medio-lateral (roll) and antero-posterior (pitch) planes was measured using a body-mounted gyroscope (SwayStar) during walking on a 4.5 m long instrumented walkway. Of the 284 older adults (mean age 76.8, 54.6% women) in this sample, the mean ± SD value of roll and pitch angles were 6.0 ± 2.0° and 6.7 ± 2.2° respectively. Older women showed significantly greater trunk sway in both roll and pitch angles than older men (p < 0.01). In both men and women, there was no significant association of roll angle with age although gait velocity decreased with increasing age. The relationship between roll angle and gait velocity was U-shaped for the overall sample. Among the subgroup with clinically normal gait, increased roll angle was associated with increased gait velocity (p < 0.001). However, there was no significant relationship between roll angle and gait velocity among the subgroup with abnormal gait. Therefore, the relationship between medio-lateral trunk sway and gait velocity differs depending on whether gait is clinically normal.We conclude that trunk sway during walking should be interpreted with consideration of both gait velocity and presence of gait abnormality in older adults.     

Quantitative trunk sway and prediction of incident falls in older adults

Poor balance and balance impairments are major predictors of falls. The purpose of the current study was to determine the clinical validity of baseline quantitative static trunk sway measurements in predicting incident falls in a cohort of 287 community-dwelling non-demented older Americans (mean age 76.14 ± 6.82 years; 54% female). Trunk sway was measured using the SwayStar™ device, and quantified as angular displacement in degrees in anterior-posterior (pitch) and medio-lateral (roll) planes. Over a one-year follow-up period, 66 elders (23%) reported incident falls. Anterior-posterior angular displacement was a strong predictor of incident falls in older adults in Cox proportional hazards models (hazard ratio adjusted for age, gender, education, RBANS total score, medical comorbidities, geriatric depression scale score, sensory impairments, gait speed, and history of fall in the past 1 year ((aHR) = 1.59; p = 0.033) whereas, angular displacement in the medio-lateral plane was not predictive of falls (aHR = 1.35; p = 0.276). Our results reveal the significance of quantitative trunk sway, specifically anterior-posterior angular displacement, in predicting incident falls in older adults.     

Effect of gait retraining for reducing ambulatory knee load on trunk biomechanics and trunk muscle activity

The purpose of this study was to test the hypothesis that walking with increased medio-lateral trunk sway is associated with lower external knee adduction moment and lower extremity muscle activation, and higher external ipsilateral trunk moment and trunk muscle activity than walking with normal trunk sway in healthy participants. Fifteen participants performed walking trials with normal and increased medio-lateral trunk sway. Maximum trunk sway, first maximum knee adduction moment, lateral trunk bending moment, and bilateral vastus medialis, vastus lateralis, gluteus medius, rectus abdominis, external oblique and erector spinae muscle activity were computed. Walking with increased trunk sway was associated with lower maximum knee adduction moment (95% confidence interval (CI): 0.50–0.62 Nm/kg vs. 0.62–0.76 Nm/kg; P < .001) and ipsilateral gluteus medius (−17%; P = .014) and erector spinae muscle activity (−24%; P = .004) and greater maximum lateral trunk bending moment (+34%; P < .001) and contralateral external oblique muscle activity (+60%; P = .009). In all participants, maximum knee adduction moment was negatively correlated and maximum trunk moment was positively correlated with maximum trunk sway. The results of this study suggest that walking with increased trunk sway not only reduces the external knee adduction moment but also alters and possibly increases the load on the trunk. Hence, load-altering biomechanical interventions should always be evaluated not only regarding their effects on the index joint but on other load-bearing joints such as the spine.     

Trunk sway measures of postural stability during clinical balance tests: effects of a unilateral vestibular deficit

This research evaluated whether quantified measures of trunk sway during clinical balance tasks are sensitive enough to identify a balance disorder and possibly specific enough to distinguish between different types of balance disorder. We used a light-weight, easy to attach, body-worn apparatus to measure trunk angular velocities in the roll and pitch planes during a number of stance and gait tasks similar to those of the Tinetti and CTSIB protocols. The tasks included standing on one or two legs both eyes-open and closed on a foam or firm support-surface, walking eight tandem steps, walking five steps while horizontally rotating or pitching the head, walking over low barriers, and up and down stairs. Tasks were sought, which when quantified might provide optimal screening for a balance pathology by comparing the test results of 15 patients with a well defined acute balance deficit (sudden unilateral vestibular loss (UVL)) with those of 26 patients with less severe chronic balance problems caused by a cerebellar-pontine-angle-tumour (CPAT) prior to surgery, and with those of 88 age- and sex-matched healthy subjects. The UVL patients demonstrated significantly greater than normal trunk sway for all two-legged stance tasks especially those performed with eyes closed on a foam support surface. Sway was also greater for walking while rotating or pitching the head, and for walking eight tandem steps on a foam support surface. Interestingly, the patients could perform gait tasks such as walking over barriers almost normally, however took longer. CPAT patients had trunk sway values intermediate between those of UVL patients and normals. A combination of trunk sway amplitude measurements (roll angle and pitch velocity) from the stance tasks of standing on two legs eyes closed on a foam support, standing eyes open on a normal support surface, as well as from the gait tasks of walking five steps while rotating, or pitching the head, and walking eight tandem steps on foam permitted a 97% correct recognition of a normal subject and a 93% correct recognition of an acute vestibular loss patient. Just over 50% of CPAT patients could be classified into a group with intermediate balance deficits, the rest were classified as normal. Our results indicate that measuring trunk sway in the form of roll angle and pitch angular velocity during five simple clinical tests of equilibrium, four of which probe both stance and gait control under more difficult sensory conditions, can reliably and quantitatively distinguish patients with a well defined balance deficit from healthy controls. Further, refinement of these trunk sway measuring techniques may be required if functions such as preliminary diagnosis rather than screening are to be attempted.     

Vibrotactile tilt feedback improves dynamic gait index: A fall risk indicator in older adults

The purpose of this study was to determine the effectiveness of vibrotactile feedback of body tilt in improving dynamic gait index (DGI) a fall risk indicator in community dwelling older adults. Twelve healthy elderly subjects (three males and nine females, age 79.7 ± 5.4 yrs) were tested in an institutional balance rehabilitation laboratory to investigate changes between the feedback off and on conditions. Subjects were acutely exposed to a vibrotactile display that indicated the magnitude and direction of their body tilt from the vertical. DGI and mediolateral (ML) sway were determined during locomotion with, and without, vibrotactile tilt feedback (VTTF). All subjects were at risk for falls based on their initial DGI Score (range: 15–19, mean 17.4 ± 1.56), which was taken with the vibratory stimulus turned off. Subjects learned to use the trunk tilt information from the vibrotactile feedback vest through 20–30 min of gait and balance training consisting of activities that challenged their balance. Subjects were then retested on the DGI. Statistically significant changes were demonstrated for the DGI total score while using the vibrotactile tilt feedback. DGI total scores improved from 17.1 ± 0.4 to 20.8 ± 0.3 (p < 0.05). We conclude that vibrotactile tilt feedback improves both control of mediolateral sway during gait and dynamic gait index. Both are fall risk indicators for this population.     

Effects of Levodopa on Postural Strategies in Parkinson's disease

Altered postural control and balance are major disabling issues of Parkinson's disease (PD). Static and dynamic posturography have provided insight into PD's postural deficits; however, little is known about impairments in postural coordination. We hypothesized that subjects with PD would show more ankle strategy during quiet stance than healthy control subjects, who would include some hip strategy, and this stiffer postural strategy would increase with disease progression.We quantified postural strategy and sway dispersion with inertial sensors (one placed on the shank and one on the posterior trunk at L5 level) while subjects were standing still with their eyes open. A total of 70 subjects with PD, including a mild group (H&Y≤2, N = 33) and a more severe group (H&Y≥3, N = 37), were assessed while OFF and while ON levodopa medication. We also included a healthy control group (N = 21).Results showed an overall preference of ankle strategy in all groups while maintaining balance. Postural strategy was significantly lower ON compared to OFF medication (indicating more hip strategy), but no effect of disease stage was found. Instead, sway dispersion was significantly larger in ON compared to OFF medication, and significantly larger in the more severe PD group compared to the mild. In addition, increased hip strategy during stance was associated with poorer self-perception of balance.     

Load distribution and postural changes in young adults when wearing a traditional backpack versus the BackTpack

Backpacks lead to poor posture due to the posterior placement of the load, which overtime may contribute to low back pain and musculoskeletal complications. This study examined postural and load distribution differences between a traditional backpack (BP) and a nontraditional backpack (BTP) in a young adult population. Using a 3D motion analysis system, 24 healthy young adults (22.5 ± 2.5 years, 12 male) completed both static stance and walking trials on a treadmill with No Load and with 15% and 25% of their body weight using the two different backpacks. There was a significant difference in trunk angle, head angle, and lower extremity joint mechanics between the backpack and load conditions during walking (p < .05). Notably, relative to the No Load condition, trunk angle decreased approximately 14° while head angle increased approximately 13° for the BP 25% state on average. In contrast, average trunk and head angle differences for the BTP 25% state were approximately 7.5° and 7°, respectively. There was also a significant difference in head angle from pre- to post-walk (p < .05) across backpacks, loads, and time. Taken together, the results indicate that the BTP more closely resembled the participants’ natural stance and gait patterns as determined by the No Load condition. The more upright posture supported by the BTP may help reduce characteristics of poor posture and, ideally, help to reduce low back pain while carrying loads.     

Gait modification strategies in trunk over right stance phase in patients with right anterior cruciate ligament deficiency

This study aimed to investigate the gait modification strategies of trunk over right stance phase in patients with right anterior cruciate ligament deficiency (ACL-D). Thirty-six patients with right chronic ACL-D were recruited, as well as 36 controls. A 3D optical video motion capture system was used during gait and stair ambulation. Kinematic variables of the trunk and kinematic and kinetic variables of the knee were calculated. Patients with chronic right ACL-D exhibited many significant abnormalities compared with controls. Trunk rotation with right shoulder trailing over the right stance phase was lower in all five motion patterns (P < 0.05). Compared with controls, trunk posterior lean was higher from descending stairs to walking when the knee sagittal plane moment ended (P < 0.01). Trunk lateral flexion to the left was higher when ascending stairs at the start of right knee coronal plane moment (P = 0.01), when descending stairs at the maximal knee coronal plane moment (P < 0.01), and when descending stairs at the end of the knee coronal plane moment (P = 0.03). Trunk rotation with right shoulder forward was higher at the minimal knee transverse plane moment (P < 0.01) and when the knee transverse plane moment ended (P < 0.01); during walking, trunk rotation with right shoulder trailing was lower at other knee moments during other walking patterns (all P < 0.01). In conclusion, gait modification strategies of the trunk were apparent in patients with ACL-D. These results provide new insights about diagnosis and rehabilitation of chronic ACL-D (better use of walking and stair tasks as part of a rehabilitation program).     

Therapeutic effect of functional electrical stimulation-triggered gait training corresponding gait cycle for stroke

The purpose of this study was to determine the therapeutic effects of functional electrical stimulation (FES) applied to the gluteus medius and tibialis anterior muscles during the gait cycle in individuals with hemiparetic stroke. Eighteen patients who had suffered a stroke were enrolled in this study. The participants were divided into either the gluteus medius and tibialis anterior (GM + TA) training group (n = 9) or the control group (n = 9). The GM + TA group received FES-triggered gait training to the gluteus medius (GM) in the stance phase and the tibialis anterior (TA) in the swing phase for 30 min, 5 session a week over a 6-week period, and control group who received only gait training without FES-triggered for the same duration of time. A foot-switch sensor was used to trigger the device in the stance (GM) and swing (TA) phases of the gait cycle reciprocally. This study measured three types of outcome measures, including spatiotemporal gait parameters, muscles activities, and balance function. After 6 weeks training, there was a significant improvement in gait velocity, cadence, stride length, and gait symmetry in the GM + TA training group compared to the control group. Dynamic balance function was significantly improved in the GM + TA training group compared to the control group. The mean changeable values of the GM was significantly greater strength in the GM + TA training group than the control group. These findings suggest that FES-triggered gait training of the GM in the stance phase and TA in the swing phase may improve the spatiotemporal parameters of gait in persons with hemiparetic stroke.     

The energy cost for balance control during upright standing

The aim of this study was to investigate whether balance control during a static upright standing task with and without balance perturbations elicits a significant and meaningful metabolic energy demand and to test whether this energy demand correlates with conventional posturography measures for balance control. Ten healthy subjects were assessed in four 4-min upright standing conditions on a force platform while energy consumption was measured using open circuit respirometry. In the reference condition subjects stood upright in parallel stance without balance perturbation (PS). In the other conditions balance was perturbed by placing the subjects in tandem stance (TS), in tandem stance blind folded (TSBF) and in tandem stance on a balance board (TSBB). Gross and net energy consumption was assessed and various conventional posturography measures were derived from the excursion of the center of pressure (CoP) of the ground reaction force. Energy consumption was substantially affected by all balance perturbations, compared to the reference condition. The highest increase in energy consumption was found for the TSBF condition (increase of 0.86 J kg^?1 s^?1 or 60% of PS). Significant correlations were found between energy consumption and posturography measures. The strongest correlation was found between gross energy consumption and the CoP path and normalized CoP path along the anterior–posterior axis (resp. r = 0.57 and r = 0.66, p < 0.001). It was concluded that the effort for balance control can elicit a meaningful metabolic energy demand. Conventional posturography provided significant, though moderate, predictors of this metabolic effort for balance control.     

Bracing the trunk and neck in young adults leads to a more aged-like gait

Older individuals typically walk at slower speeds, with shorter step lengths, greater step widths and spend a larger proportion of the gait cycle in double stance. Changes in neck and trunk mobility may underlie some of the changes in walking seen with increasing age. Consequently, this study was designed to assess whether externally increasing trunk/neck stiffness in young adults leads to similar changes in gait pattern observed with aging. Twelve young adults (20–29 years), sixteen old adults (60–69 years) and fifteen older adults (70–79 years) walked across a 20′ pressure sensitive GAITRite© instrumented walkway at their preferred speed. The young adults also walked under three bracing conditions: (1) Neck braced, (2) Trunk braced, and (3) Neck and Trunk braced. The results revealed that the old and older age groups walked significantly slower, with a shorter step length and with a narrower base of support (p’s < 0.05) compared to the young adults. In young adults, combined neck and trunk bracing led to reduced walking speed, shorter step length, wider base of support and a larger proportion of the gait cycle spent in double stance (p’s < 0.05). The walking speed and step length of older adults remained less than fully braced young adults (p’s < 0.05). Overall these results indicate that artificially stiffening the trunk and neck of young individuals leads to systematic gait changes similar to aging. Consequently, age-related changes in mobility of the neck and torso may in part contribute to the decrements in walking seen for older adults.     

The association between intersegmental coordination in the lower limb and gait speed in elderly females

Human multi-segmental motion is a complex task requiring motor coordination. Uncoordinated motor control may contribute to the decline in mobility; however, it is unknown whether the age-related decline in intersegmental coordination relates to the decline in gait performance. The aim of this study was to clarify the association between intersegmental coordination and gait speed in elderly females. Gait measurements were performed in 91 community-dwelling elderly females over 60 years old. Foot, shank, and thigh sagittal motions were assessed. Intersegmental coordination was analyzed using the mean value of the continuous relative phase (mCRP) during four phases of the gait cycle to investigate phase differences in foot–shank and shank–thigh motions during a normal gait. The results showed that foot–shank mCRP at late stance had negative correlations with gait speed (r = −0.53) and cadence (r = −0.54) and a positive correlation with age (r = 0.25). In contrast, shank–thigh mCRP at late stance had positive correlations with gait speed (r = 0.37) and cadence (r = 0.56). Moreover, partial correlation, controlling age, height, and weight, revealed that foot–shank mCRP at late stance had negative correlations with gait speed (r = −0.52) and cadence (r = −0.54). Shank–thigh mCRP at late stance had a positive correlation with gait speed (r = 0.28) and cadence (r = 0.51). These findings imply that the foot–shank and shank–thigh coordination patterns at late stance relate to gait speed, and uncoordinated lower limb motion is believed to be associated with the age-related decline in cadence.     

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

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

Effect of age on the ability to recover from a single unexpected underfoot perturbation during gait: Kinematic responses

A sudden underfoot perturbation can present a serious threat to balance during gait, but little is known about how humans recover from such perturbations or whether their response is affected by age. We tested the hypothesis that age would not affect the stepping responses to a nominal 10 degree inversion or eversion of the stance foot during gait. Twenty-three healthy young (22.7 ± 3.35 yrs) and 18 healthy old adults (68.0 ± 7.19 yrs) performed 60 walking trials along a 6-m level walkway at a normal gait speed. In 16 of these trials, a single medial (MP) or lateral (LP) perturbation was randomly administered once under the left or right foot. Recovery step width (SW), step length (SL), trunk kinematics and walking speed were measured optoelectronically. Repeated-measures analysis of variance and post hoc t-tests were used to test the hypotheses. The results show that a MP or LP altered the recovery SL (p = 0.005) and age affected the number of recovery steps (p = 0.017), as well as the first recovery SW and SL (p = 0.013 and p = 0.031, respectively). Both MP and LP caused young adults to have wider SW (p < 0.02) and shorter SL (p < 0.005) without changing trunk movement during their first recovery step. Older adults, however, significantly changed lateral trunk inclination during the first recovery step, decreased their fourth recovery SL (p < 0.001). We conclude that young adults adjust the step kinematics of as many as four recovery steps following this perturbation, a response that was delayed and significantly weaker in older adults who instead exhibited an immediate torso inclination consistent with a hip response strategy.     

Haptic feedback from manual contact improves balance control in people with Parkinson's disease

Parkinson's disease (PD) degrades balance control. Haptic (touch and proprioception) feedback from light contact with a stationary surface inadequate to mechanically stabilize balance improves balance control in healthy people. In this study we tested whether PD impairs use of haptic cues independent of mechanical support to control balance. We measured postural sway in thirteen individuals with PD (H&Y 1–3, median = 2, Q₁ = 2, Q₃ = 2) and thirteen age-matched controls balancing in a widened, sharpened Romberg stance in four conditions: eyes-closed, no manual contact; eyes-closed light-touch contact (<1 N), eyes-closed, unrestricted contact; and eyes-open, no contact. To determine whether PD-severity affects any of these balance strategies, PD participants were tested on- and off-medication, and using the more- and less-affected body side in the stance and manual contact.Individuals with PD simultaneously maintained non-supportive fingertip contact and balance in this task without practice. PD participants swayed more than control participants (ML CP p = 0.010; shoulder p < 0.001), but manual contact reduced sway. Non-supportive manual contact stabilized balance more than vision (p < 0.05). PD-severity factors had no significant effect (p > 0.05).We conclude the effect of PD on balance is not specific to vision or haptic feedback. Nevertheless, haptic cues from manual contact, independent of mechanical support, improve balance control in individuals with PD. We discuss the implication that PD or associated dopaminergic pathways do not directly affect haptic feedback balance control mechanisms, including arm/posture coordination and proprioceptive integration.     

No differences in tandem gait performance between male and female athletes acutely post-concussion

ObjectivesTo test whether 1) concussed athletes demonstrate slower tandem gait times compared to controls and 2) concussed female athletes display greater post-injury deficits than males.DesignProspective longitudinalMethodFifty concussed collegiate student-athletes (32% female, age = 20.18 ± 1.27 years) completed tandem gait tests during pre-season (Time 1) and acutely (<72 hours) post-concussion (Time 2), and twenty-five controls (52% female, age = 21.08 ± 2.22 years) completed tandem gait at two time points, 1.96 ± 0.46 days apart. Participants completed four single-task (ST) and dual-task (DT) trials. During DT trials, they simultaneously completed a cognitive assessment. The best ST and DT times were recorded, along with cognitive accuracy, and the change score between the two assessments was calculated. A positive change in tandem gait time was indicative of worsening performance. A 2 × 2 (group*sex) ANOVA was used to examine change between pre-injury and post-injury tests for ST/DT tandem gait time and DT cognitive accuracy.ResultsThe change in tandem gait time from Time 1 to Time 2 was significantly higher for the concussion group relative to controls during both ST (Concussion: 1.36 ± 2.6 seconds, Controls: -1.16 ± 0.8 seconds, p < 0.001) and DT (Concussion: 1.70 ± 3.8 seconds, Controls: -0.94 ± 1.7 seconds, p = 0.002) tandem gait. There were no interactions or main effects of sex for tandem gait time or cognitive accuracy.ConclusionsThere were no sex-specific differences in the change in tandem gait performance among concussed collegiate athletes or controls. However, all concussed participants, regardless of sex, performed significantly worse on tandem gait than male and female controls, who both improved between testing time points.     

Trunk muscle action compensates for reduced quadriceps force during walking after total knee arthroplasty

Patients with total knee arthroplasty (TKA) frequently exhibit changes in gait biomechanics post-surgery, including decreased ranges of joint motion and changes in joint loading; however, the actions of the lower-limb muscles in generating joint moments and accelerating the center of mass (COM) during walking are yet to be described. The aim of the present study was to evaluate differences in lower-limb joint kinematics, muscle-generated joint moments, and muscle contributions to COM accelerations in TKA patients and healthy age-matched controls when both groups walk at the same speed. Each TKA patient was fitted with a posterior-stabilized total knee replacement and underwent patellar resurfacing. Three-dimensional gait analysis and subject-specific musculoskeletal modeling were used to determine lower-limb and trunk muscle forces and muscle contributions to COM accelerations during the stance phase of gait. The TKA patients exhibited a ‘quadriceps avoidance’ gait pattern, with the vasti contributing significantly less to the extension moment developed about the knee during early stance (p = 0.036). There was a significant decrease in the contribution of the vasti to the vertical acceleration (support) (p = 0.022) and forward deceleration of the COM (braking) (p = 0.049) during early stance; however, the TKA patients compensated for this deficiency by leaning their trunks forward. This significantly increased the contribution of the contralateral back extensor muscle (erector spinae) to support (p = 0.030), and that of the contralateral back rotators (internal and external obliques) to braking (p = 0.004). These findings provide insight into the biomechanical causes of post-operative gait adaptations such as ‘quadriceps avoidance’ observed in TKA patients.     

Clinimetric properties of the Tinetti Mobility Test,Four Square Step Test,Activities-specific Balance Confidence Scale,and spatiotemporal gait measures in individuals with Huntington's disease

Background and purposeIndividuals with Huntington's disease (HD) experience balance and gait problems that lead to falls. Clinicians currently have very little information about the reliability and validity of outcome measures to determine the efficacy of interventions that aim to reduce balance and gait impairments in HD. This study examined the reliability and concurrent validity of spatiotemporal gait measures, the Tinetti Mobility Test (TMT), Four Square Step Test (FSST), and Activities-specific Balance Confidence (ABC) Scale in individuals with HD.MethodsParticipants with HD [n = 20; mean age ± SD = 50.9 ± 13.7; 7 male] were tested on spatiotemporal gait measures and the TMT, FSST, and ABC Scale before and after a six week period to determine test–retest reliability and minimal detectable change (MDC) values. Linear relationships between gait and clinical measures were estimated using Pearson's correlation coefficients.ResultsSpatiotemporal gait measures, the TMT total and the FSST showed good to excellent test–retest reliability (ICC > 0.75). MDC values were 0.30 m/s and 0.17 m/s for velocity in forward and backward walking respectively, four points for the TMT, and 3 s for the FSST. The TMT and FSST were highly correlated with most spatiotemporal measures. The ABC Scale demonstrated lower reliability and less concurrent validity than other measures.ConclusionsThe high test–retest reliability over a six week period and concurrent validity between the TMT, FSST, and spatiotemporal gait measures suggest that the TMT and FSST may be useful outcome measures for future intervention studies in ambulatory individuals with HD.     

Directional effects of biofeedback on trunk sway during gait tasks in healthy young subjects

Biofeedback of trunk sway is a possible remedy for patients with balance disorders. Because these patients have a tendency to fall more in one direction, we investigated whether biofeedback has a directional effect on trunk sway during gait.Forty healthy young participants (mean age 23.1 years) performed 10 gait tasks with and without biofeedback. Combined vibrotactile, auditory and visual feedback on trunk sway in either the lateral or anterior–posterior (AP) direction was provided by a head-mounted actuator system. Trunk roll and pitch angles, calculated from trunk angular velocities measured with gyroscopes, were used to drive the feedback.A reduction in sway velocities occurred across all tasks regardless of feedback direction. Reductions in sway angles depended on the task. Generally, reductions were greater in pitch. For walking up and down stairs, or over barriers, pitch angle reductions were greater with AP than lateral feedback. For tandem and normal walking, reductions were similar in pitch and roll angles for both feedback directions. For walking while rotating or pitching the head or with eyes closed, only pitch angle was reduced for both feedback directions.These results indicate that the central nervous system is able to incorporate biofeedback of trunk sway from either the AP or lateral direction to achieve a reduction in both pitch and roll sway. Greater reductions in pitch suggest a greater ability to use this direction of trunk sway biofeedback during gait.