The high-level mobility assessment tool (HiMAT) for traumatic brain injury. Part 2: content validity and discriminability.

PRIMARY OBJECTIVES: (i) To assess the measurement properties of the high-level mobility assessment tool (HiMAT) for people with traumatic brain injury (TBI), (ii) to measure the extent to which the HiMAT is a uni-dimensional, discriminative hierarchical outcome scale. RESEARCH DESIGN: The content validity was assessed using a three-stage process of investigating internal consistency, factor analysis and Rasch analysis. The uni-dimensionality of the HiMAT items was also tested. Discriminability was investigated by correlating raw and logit scores obtained from Rasch analysis. The study was conducted at a major rehabilitation facility using a convenience sample of 103 adults with TBI. MAIN OUTCOMES AND RESULTS: The internal consistency for the high-level items was very high (Cronbach's alpha = 0.99). Principal axis factoring identified several balance items as belonging to a second factor not related to high-level mobility, hence these items were excluded. Rasch analysis identified several misfitting items, such as walking around a figure of eight and stopping from a run, which were also excluded. Logit scores were used to exclude clustered and, therefore, redundant items. Raw scores correlated very highly (r = 0.98) with logit scores, indicating that raw scores provided good discriminability and were suitable for use by clinicians. CONCLUSION: The HiMAT, which assesses higher-level mobility requirements of people with TBI for return to pre-accident social, leisure and sporting activities, is a uni-dimensional and discriminative scale for quantifying therapy outcomes.

Effect of stroke on step characteristics of obstacle crossing.

OBJECTIVE: To compare spatial and temporal measures during lead limb obstacle crossing between subjects with stroke and healthy subjects. DESIGN: Experimental, observational, with matched controls. SETTING: Geriatric rehabilitation unit in a tertiary referral hospital. PARTICIPANTS: Distance data were available for 19 subjects with stroke and 19 able-bodied subjects. Temporal data were available for 16 subjects with stroke and 16 able-bodied subjects. Subjects with stroke were inpatients and had to be able to walk 10 meters without assistance or gait aid. INTERVENTION: Subjects were required to step over high and wide obstacles, ranging from 1 to 8cm, and trials were videotaped. MAIN OUTCOME MEASURES: Toe clearance, preobstacle distance, postobstacle distance, step length, proportion of step length preobstacle, step time, preobstacle step time, postobstacle step time, and proportion of step time preobstacle were measured. RESULTS: Mann-Whitney U tests were performed to determine differences between the 2 groups. Subjects with stroke had significantly higher toe clearance, smaller postobstacle distances, and greater step times than healthy subjects. Subjects with stroke did not demonstrate a significant reduction in preobstacle distance. CONCLUSION: By modifying their lead limb trajectory during obstacle crossing, persons with stroke reduce the risk of a trip due to toe contact, but the modification may expose them to other safety risks.

Theoretical considerations in balance assessment.

Although balance control is an integral component of all daily activities, its complex and flexible nature makes it difficult to assess adequately. This paper discusses balance by examining it in relation to function and the physical environment. Balance is affected by both the task being undertaken and the surroundings in which it is performed. Different tasks and environments alter the biomechanical and information processing needs for balance control. These issues are discussed and a modification of Gentile s Taxonomy of Tasks is suggested for analysis of clinical balance tests, some of which are used as examples.

A prospective study of injuries in basketball: a total profile and comparison by gender and standard of competition.

The study aimed to determine prospectively a basketball injury profile, including severity of injury, and to compare the injury profile by gender and standard of competition. Trained observers viewed basketball games, noting the occurrence of injuries, and confirmed injuries by questioning all players on site after the game. Injured players completed a questionnaire and the progress of their injury was monitored by telephone interview. A total of 10,393 basketball participations were observed. An overall injury rate was documented of 18.3 per 1,000 participations (24.7 per 1,000 playing hours), and was comparable by gender and standard of competition. Serious injuries (missing one or more weeks of play) occurred at a rate of 2.89/1,000 participations; with the ankle joint the most common serious injury (1.25/1,000 participations), followed by the calf/anterior leg (0.48/1,000 participations) and knee joint (0.29/1,000 participations). The severity of the injury was significantly associated with the body region injured, with more serious injuries incurred to the lower limb than other body regions (p <.05). The severity of the injury incurred was not related to the standard of competition, gender, age, height, number of games played per week, amount of training undertaken, type of injury, or the mechanism of injury (p> .05).

Gait after stroke: initial deficit and changes in temporal patterns for each gait phase.

OBJECTIVE: To examine which phases of the gait cycle contributed to decreased gait velocity after stroke. DESIGN: Experimental. SETTING: Inpatient rehabilitation centers. PARTICIPANTS: Forty-two patients with unilateral first stroke who were able to walk 10 meters; and 42 age- and gender-matched controls with no history of stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Deficit and change expressed as duration (s) and proportion (%) for the 4 phases of the gait cycle at the time of admission to rehabilitation (test 1), a median of 31 days poststroke onset, and again 8 weeks later (test 2). Affected and unaffected single-limb support (SLS) and initial double-limb support (DLS) were compared. RESULTS: At tests 1 and 2, the durations of the 2 DLS and unaffected SLS phases were significantly (p <.001) longer in the stroke patients than in control subjects. No difference was found between the 2 groups for duration of affected SLS at either test time. Significant (p <.001) decreases occurred over the 8-week period in the 3 phases identified to be abnormally long at test 1. CONCLUSION: If the goal of rehabilitation is to increase gait velocity and normalize the gait pattern, treatment should focus on decreasing the DLS and unaffected SLS phases of the gait cycle.

Ankle injuries in basketball: injury rate and risk factors.

OBJECTIVES: To determine the rate of ankle injury and examine risk factors of ankle injuries in mainly recreational basketball players. METHODS: Injury observers sat courtside to determine the occurrence of ankle injuries in basketball. Ankle injured players and a group of non-injured basketball players completed a questionnaire. RESULTS: A total of 10 393 basketball participations were observed and 40 ankle injuries documented. A group of non-injured players formed the control group (n = 360). The rate of ankle injury was 3.85 per 1000 participations, with almost half (45.9%) missing one week or more of competition and the most common mechanism being landing (45%). Over half (56.8%) of the ankle injured basketball players did not seek professional treatment. Three risk factors for ankle injury were identified: (1) players with a history of ankle injury were almost five times more likely to sustain an ankle injury (odds ratio (OR) 4.94, 95% confidence interval (CI) 1.95 to 12.48); (2) players wearing shoes with air cells in the heel were 4.3 times more likely to injure an ankle than those wearing shoes without air cells (OR 4.34, 95% CI 1.51 to 12.40); (3) players who did not stretch before the game were 2.6 times more likely to injure an ankle than players who did (OR 2.62, 95% CI 1.01 to 6.34). There was also a trend toward ankle tape decreasing the risk of ankle injury in players with a history of ankle injury (p = 0.06). CONCLUSIONS: Ankle injuries occurred at a rate of 3.85 per 1000 participations. The three identified risk factors, and landing, should all be considered when preventive strategies for ankle injuries in basketball are being formulated.

Angular movements of the pelvis and lumbar spine during self-selected and slow walking speeds.

We studied the effect of walking at a self-selected and at a slower speed on the angular movements of the pelvis and lumbar spine. We also studied how interpretation of speed effects on lumbar spine movements was influenced by frame of reference, either relative to the pelvis or relative to a global reference frame. Twenty-seven subjects without pathology walked on a treadmill at either self-selected or 60% of self-selected speed. The movements of the pelvis and lumbar spine, as represented by surface markers, were recorded by videocameras and the three-dimensional angles computed by the PEAK motion measurement system. Results indicated that the amplitudes of pelvic list (P<0.05) and pelvic axial rotation (P<0. 05) were decreased at slow walking speed. Relative to the pelvis, the amplitude of lumbar lateral flexion was decreased with slower walking (P<0.01). In contrast, when lumbar spine movements were measured relative to a global reference frame, no differences were detected due to decreased walking speed. This suggests, firstly, that the effect of walking speed when evaluating the significance of decreased movements of the pelvis and of the lumbar spine (relative to the pelvis) of subjects walking at slower than self-selected speeds should be considered and secondly, that movement of the lumbar spine should be interpreted with respect to a frame of reference.

Obstacle crossing in subjects with stroke.

OBJECTIVE: To study the ability of subjects with stroke to successfully step over an obstacle during ambulation. SETTING: A geriatric rehabilitation unit in a tertiary referral hospital. SUBJECTS: Twenty-four inpatients with stroke (median time poststroke 27 days, interquartile range 21 to 44.5 days) able to walk 10 m unassisted without walking aids; also, 22 healthy subjects. METHOD: Subjects were required to step over obstacles of various heights and widths, ranging from 1cm to 8cm. A fail was scored if the obstacle was contacted by either lower limb or if assistance or upper limb support was required. The choice of leading limb and the presence of visual deficits and neglect were also recorded in the stroke subjects. Subjects were tested on two occasions. RESULTS: Significantly more fails were recorded for stroke subjects, with 13 subjects failing at least once. No preference was shown for leading either with the affected or with the unaffected leg. Stroke subjects showed inconsistent performance over the two testing sessions. CONCLUSION: The ability to negotiate obstacles was compromised and inconsistent in stroke subjects undergoing inpatient rehabilitation. This suggests that gait safety in this population remains threatened.

Walking speed on parquetry and carpet after stroke: effect of surface and retest reliability.

OBJECTIVE: At the transition stage from rehabilitation to home this study aimed to (1) investigate the effect of floor surface (carpet and parquetry) on walking speed; (2) investigate whether there was a difference between these surfaces as stroke patients voluntarily increased from comfortable to fast pace; (3) investigate whether walking speed on parquetry was a predictor of walking speed on carpet at the two paces; (4) investigate whether walking speed at a comfortable pace was a predictor of walking speed at a fast pace on the two surfaces; and (5) quantify systematic and random error in repeated measurements for fast-paced walking trials. DESIGN: Subjects walked 10 metres at comfortable and fast paces on carpet and parquetry on two consecutive days. SETTING: Inpatient rehabilitation centre. SUBJECTS: Twenty-four stroke patients. MAIN OUTCOME MEASURE: Walking speed. RESULTS: Two-way analysis of variance confirmed that patients walked more slowly on carpet than parquetry (F(1,23) = 5.3, p <0.05) at both paces; the interaction effect was not significant (p >0.05). Walking speed on parquetry was a strong predictor of walking speed on carpet at a comfortable (r = 0.92), and fast pace (r = 0.97). Walking speed at comfortable pace was a moderately strong predictor of walking speed at fast pace on parquetry (r = 0.84), and on carpet (r = 0.88). Random error in repeated measurements was higher when walking fast on carpet (7.21 m/min) and parquetry (8.32 m/min) than when walking at a comfortable pace on carpet (4.63 m/min) and parquetry (3.48 m/min). Systematic error was negligible (p <0.05). CONCLUSION: Carpet surface was more challenging than parquetry surface, as evidenced by the systematic decrease in walking speed. This may have been due to lack of familiarity. Relative to the wide range of scores in the group, stroke patients showed consistency of walking speed across both surfaces. Likewise, stroke patients retained their relative position in the group as they changed from a comfortable to a fast walking pace. The difference in random error between comfortable and fast-paced trials highlights the need to quantify error in the repeated measurement situation according to specific test conditions.

Prediction of gait velocity in ambulatory stroke patients during rehabilitation.

OBJECTIVE: To quantify prediction of gait velocity in ambulatory stroke patients during rehabilitation. DESIGN: Single group (n = 42) at the beginning of rehabilitation (Test 1) and 8 weeks later (Test 2). SETTING: Inpatient rehabilitation. PATIENTS: Unilateral first stroke; informed consent; able to walk 10 meters. INDEPENDENT VARIABLES: Gait velocity at Test 1, age, time from stroke to Test 1, side of lesion, neglect. DEPENDENT VARIABLES: Gait velocity at Test 2, gait velocity change. RESULTS: The correlation between initial gait velocity and gait velocity outcome at Test 2 was of moderate strength (r2 = .62, p<.05). However, even at its lowest, the standard error of prediction for an individual patient was 9.4 m/min, with 95% confidence intervals extending over a range of 36.8 m/min. Age was a weak predictor of gait velocity at Test 2 (r2 = -.10, p<.05). Gait velocity change was poorly predicted. The only significant correlations were initial gait velocity (r2 = .10, p<.05) and age (r2 = .10, p<.05). CONCLUSION: While the prediction of gait velocity at Test 2 was of moderate strength on a group basis, the error surrounding predicted values of gait velocity for a single patient was relatively high, indicating that this simple approach was imprecise on an individual basis. The prediction of gait velocity change was poor. A wide range of change scores was possible for patients, irrespective of their gait velocity score on admission to rehabilitation.

Quantifying lateral pelvic displacement during walking.

OBJECTIVE: The purpose of this investigation was to test a new procedure for quantifying lateral pelvic displacement during walking. DESIGN: A quasi-experimental design was used to quantify the gait of 18 unimpaired people and one person with hemiplegia. BACKGROUND: Although previous techniques provided useful information on amplitude of lateral pelvic displacement, they did not consider step-to-step variations in walking direction or enable quantification of symmetry. METHODS: Three-dimensional motion analysis was used to collect the coordinates of light-reflective markers placed on the scarum and heels of each subject. Subjects performed one 10 m overground walk at their preferred speed. Amplitude and symmetry of lateral pelvic displacement were quantified relative to the step-to-step variation in the path of motion (base of support). RESULTS: The mean amplitude of lateral pelvic displacement for the unimpaired group was 40.8 mm, and symmetry was 3.1 mm. The amplitude of lateral pelvic displacement for the hemiplegic person was 88.4 mm. Symmetry was 30.9 mm, with deviation toward the non-paretic side. CONCLUSION: The new procedure provided information on the amplitude and symmetry of lateral pelvic displacement in unimpaired adults and was sensitive to deviations of a person with a walking abnormality. RELEVANCE: Treatment of atypical lateral pelvic displacement is frequently an aim of stroke rehabilitation. Therefore, it is important to have objective, accurate methods of quantification.

Systematic and random error in repeated measurements of temporal and distance parameters of gait after stroke.

OBJECTIVE: To obtain intersession estimates of error for temporal and distance (TD) parameters of gait in a sample of stroke patients undertaking inpatient rehabilitation. DESIGN: Thirty-one stroke patients were measured with an instrumented footswitch system (after a median of 46 days poststroke; interquartile range = 26 to 63) walking over a 10-meter distance a total of four times on 3 consecutive days. Two familiarization walks provided intrasession retest data. RESULTS: Metric estimates of systematic and random error have been provided for obtained TD parameters. Proportional indices of reliability (ICC [2,1] and Pearson's r) were generally high, ranging from .72 to .94. CONCLUSION: By quantifying systematic and random error associated with the process of repeated measurements, criteria have been provided for evaluating change in TD variables during rehabilitation. Although error for gait velocity was small relative to individual differences in the stroke group, it was large relative to levels of change derived from measurements reported during typical periods of rehabilitation. Serial measurements of gait during rehabilitation may be better than two consecutive measurements. This study highlights the need to interpret estimates of error according to the purpose of measurement.

Angular movements of the lumbar spine and pelvis can be reliably measured after 4 minutes of treadmill walking.

OBJECTIVE: To determine the familiarization period required to obtain consistent measurements of the angular movements of the lumbar spine and pelvis during treadmill walking. DESIGN: An in vivo study with repeated measures every 2 min over 10 min. BACKGROUND: Walking on a treadmill can initially be an unfamiliar experience. No data were available to indicate the length of time required for treadmill familiarization prior to taking measurements of the angular movements of the lumbar spine and pelvis. The familiarization period has implications for the use of this technique in clinical testing. METHODS: The angular movements of the lumbar spine and pelvis were examined by thePEAK 3D motion measurement system in 16 untrained, normal subjects walking for 10 min on a treadmill at either self-selected or 60% of self-selected speed. RESULTS: The reliability of the angular measurements of the spine and pelvis were all greater than 0.83 (ICC) after 4 min of treadmill walking and did not appear to increase after 4 min. No changes in the amplitudes of the angular movements of the lumbar spine and pelvis could be detected after 4 min of treadmill walking, or of the absolute difference scores beyond 2 min of treadmill walking, in either normal or slow-speed walking groups. CONCLUSIONS: Angular movements of the lumbar spine and pelvis were consistent after 4 min of treadmill walking by normal subjects, both at self-selected and slow walking speeds, indicating that reliable measurements of these parameters could be taken at that time.

Deficit and change in gait velocity during rehabilitation after stroke.

OBJECTIVE: To quantify the initial deficit, change, and outcome in gait velocity during inpatient rehabilitation following stroke. DESIGN: The initial deficit on admission to rehabilitation was quantified by comparing 42 stroke patients with 42 controls matched by gender and age. The change in the stroke patients during the next 8 weeks was quantified and gait outcome was compared with functional and normal criteria. SETTING: Patients were referred from four inpatient rehabilitation centers at the time of admission following a median of 16.5 days in the acute hospital. SELECTION CRITERIA: ability to give informed consent; unilateral first stroke; ability to walk 10 meters. INTERVENTION: Patients participated in a median of 17.38 hours of individual physical therapy including a median of 6.92 hours of gait training during the 8 weeks. MAIN OUTCOME MEASURE: Gait velocity. RESULTS: Gait velocity was initially 38.6% (26.7m/min SD = 14.9) of the performance of controls and improved to 55.1% (38.1m/min). At outcome only 24% exceeded the 5th percentile of controls (48.1m/min) or the velocity required to cross the typical signalled intersection (46.2m/min). The change was only 26% of the initial deficit. Fifty-five percent of the patients improved beyond the 95% confidence intervals surrounding the error of measuring change. Indices of responsiveness indicated that there was a high signal-to-noise ratio and a robust effect size. CONCLUSION: Gait velocity discriminated the effect of stroke and the change during rehabilitation.

Maximum voluntary weight-bearing by the affected and unaffected legs in standing following stroke.

OBJECTIVE: To compare stroke patients to control subjects for ability to transfer body weight onto the affected and unaffected leg in standing; to investigate intra-session reliability. DESIGN: Comparative clinical study conducted within a single session. BACKGROUND: There is a paucity of quantitative data about maximum voluntary weight-bearing in patients during rehabilitation following stroke. METHODS: A Kistler force platform was used to quantify maximum amount of body weight transferred to a single limb in the lateral and forward directions during weight-shifting. Twelve control subjects matched by gender and age (median 64 years) were compared to 12 inpatient stroke patients after a median of 37 days post-onset. RESULTS: The median score for control subjects was approximately 95% of body weight to each leg in both directions. In contrast, stroke patients transferred less body weight (P<0.01) to the affected leg (65.5% lateral; 54.9% forward) and also to the unaffected leg (85.0% lateral; 80.1% forward). For the stroke patients, transfer of body weight was more challenging in the forward direction than the lateral direction on the affected leg (P<0.05). Relative to individual differences in the stroke group, error due to the repeated measurement process was low. CONCLUSION: The testing procedure was found to discriminate between stroke patients and control patients and had high retest reliability within a single session.

A comparison of the injuries sustained by female basketball and netball players.

A prospective and reliable method of injury surveillance was implemented to document a comprehensive injury profile in female basketball and netball. The study further aimed to compare the injury profiles of the two sports. Trained observers viewed basketball and netball games, noting the occurrence of injuries. Injuries were confirmed by questioning all players on site after the game. Injured players completed a questionnaire and the progress of their injury was monitored by telephone interview. A total of 16,162 player participations were observed; 6,972 for basketball and 9,190 for netball. Comparable injury rates were observed for female basketball and netball players; 18.22 and 17.30 injuries per 1,000 participations, respectively. The ankle, hand and knee were the body parts injured most frequently in both sports, whilst head and neck injuries were prevalent in basketball only. Netball players sustained severe injuries at a rate 3.3 times that of female basketball players. The major and severe injuries occurred at an average of one injury in 625 games in female basketball and one in 250 games in netball. The ankle, knee and calf/shin were the body parts most frequently involved in the more serious injuries.

The differential effects of external ankle support on postural control.

Ankle supports are commonly used in an attempt to decrease the risk of ankle injury during sport. However, their use may also impair postural control, which is an integral component of sports participation. The aim of this study was to investigate the effects of three different ankle supports (tape, brace, and elastic bandage) on postural control in 24 normal subjects with a mean age of 24.8 years (+/- 4.4). Two measures were used to evaluate postural control in one-legged stance with the eyes closed: variability of mediolateral ground reaction force (acquired from a force platform) and frequency of foot touchdowns by the nonsupport leg (assumed to indicate ability of the subject to maintain one-legged stance posture). Both measures revealed a differential effect for ankle support on postural control. The use of an elastic bandage had no significant effect on postural control (p > 0.05), while the use of tape or a brace had a significant detrimental effect (p < 0.05). While wearing the tape or a brace, subjects were less steady and touched down more frequently. Restriction of ankle movement was offered as a possible explanation for the results, since postural control was impaired only by the ankle supports which limited ankle motion. These findings may have implications regarding impaired athletic performance.

Postural control following inversion injuries of the ankle.

Postural control was investigated following unilateral inversion injury of the ankle in 24 trained and 24 untrained subjects at least 8 weeks following injury and following resumption of high-speed activities. The two groups differed in the practice of balance exercises in one-legged stance during rehabilitation. Using a force platform the variability of the mediolateral force signal was used to quantify steadiness as each subject stood in one-legged stance with the eyes open and closed on the injured and noninjured legs. A three way analysis of variance showed that for the untrained subjects postural steadiness was significantly worse on the injured leg than the noninjured leg both with eyes open (p < .05) and closed (p < .05). No postural deficit was found on the injured leg of the trained subjects with eyes open or closed (p > .05). It is strongly recommended that rehabilitation following inversion injury of the ankle include balance retraining to minimize the risk of further injury.

Retest reliability of the temporal and distance characteristics of hemiplegic gait using a footswitch system.

Using a footswitch system, the retest reliability of the temporal and distance parameters of gait was investigated within a session for 22 stroke patients in the early phase of rehabilitation. High to very high reliability was found for the temporal and distance parameters of gait, and the temporal symmetry index based on the difference in single-limb support duration between each leg (r = 0.85 to 0.98; intraclass correlation coefficients (ICC)(2,1) = 0.82 to 0.98). Significant differences were found between the two trials for velocity, stride length, and total double support (p < .05). Despite the high reliability coefficients, 95% confidence intervals, which take into account the random and systematic error, were wide for all parameters. These wide confidence intervals indicate that the use of two consecutive measurements for interpreting an individual patient's change would not be a sensitive method for monitoring progress or deterioration during rehabilitation. Strategies that may improve the clinical usefulness of temporal and distance gait measures in stroke rehabilitation are discussed. These include further reducing error sources, increasing data collection per measurement, using serial measurements on each patient, or using less rigorous confidence intervals.

Electrogoniometric feedback: its effect on genu recurvatum in stroke.

The purpose of this study was to determine the effect of combining electrogoniometric feedback with contemporary physical therapy procedures for treatment of genu recurvatum following stroke. Twenty-six patients suffering knee hyperextension resulting from cerebrovascular disorders were allocated to either a control group or an experimental group. Both groups received treatment for knee hyperextension during two consecutive phases. During phase I the control group received physical therapy and the experimental group received electrogoniometric feedback as an adjunct to physical therapy. In phase II both groups received physical therapy alone. Each phase lasted four weeks, during which time patients were treated 45 minutes daily, five days every week. Subjects in the experimental group showed greater reduction in knee hyperextension. This was particularly evident in phase II when the difference between groups for reduction in knee hyperextension reached statistical significance (U = 40, p = 0.011). These results suggest that the addition of electrogoniometric feedback to standard physical therapy enhanced the effectiveness of treatment for genu recurvatum in stroke.