Change in Low Back Movement Patterns After Neurosurgical Intervention for Lumbar Spondylosis.

OBJECTIVES: The purpose of this study was to assess the use of computer-aided combined movement examination (CME) to measure change in low back movement after neurosurgical intervention for lumbar spondylosis and to use a CME normal reference range (NRR) to compare and contrast movement patterns identified from lumbar disk disease, disk protrusion, and nerve root compression cases. METHODS: A test-retest, cohort observational study was conducted. Computer-aided CME was used to record lumbar range of motion in 18 patients, along with pain, stiffness, disability, and health self-report questionnaires. A minimal clinically important difference of 30% was used to interpret meaningful change in self-reports. z Scores were used to compare CME. Post hoc observation included subgrouping cases into 3 discrete pathologic conditions-disk disease, disk protrusion, and nerve root compression-to report intergroup differences in CME. RESULTS: Self-report data indicated that 11, 7, and 10 patients improved by ≥30% in pain, stiffness, and function, respectively. Three patients experienced clinically significant improvement in health survey. A CME pattern reduced in all directions suggested disk disease. Unilaterally restricted movement in side-flexed or extended directions suggested posterolateral disk protrusion with or without ipsilateral nerve root compression. Bilateral restrictions in extension suggested posterior disk protrusion with or without nerve root compression. In 11 of the 18 cases, CME converged toward the NRR after surgery. CONCLUSION: We described the use of CME to identify atypical lumbar movement relative to an NRR. Data from this short-term postoperative study provide preliminary evidence for CME movement patterns suggestive of disk disease, disk protrusion, and nerve root compression.

Structure-Specific Movement Patterns in Patients With Chronic Low Back Dysfunction Using Lumbar Combined Movement Examination.

OBJECTIVE: A test-retest cohort study was conducted to assess the use of a novel computer-aided, combined movement examination (CME) to measure change in low back movement after pain management intervention in 17 cases of lumbar spondylosis. Additionally we desired to use a CME normal reference range (NRR) to compare and contrast movement patterns identified from 3 specific structural pathologic conditions: intervertebral disc, facet joint, and nerve root compression. METHODS: Computer-aided CME was used before and after intervention, in a cohort study design, to record lumbar range of movement along with pain, disability, and health self-report questionnaires in 17 participants who received image-guided facet, epidural, and/or rhizotomy intervention. In the majority of cases, CME was reassessed after injection together with 2 serial self-reports after an average of 2 and 14 weeks. A minimal clinically important difference of 30% was used to interpret meaningful change in self-reports. A CME NRR (n = 159) was used for comparison with the 17 cases. Post hoc observation included subgrouping cases into 3 discrete pathologic conditions, intervertebral disc, facet dysfunction, and nerve root compression, in order to report intergroup differences in CME movement. RESULTS: Seven of the 17 participants stated that a "combined" movement was their most painful CME direction. Self-report outcome data indicated that 4 participants experienced significant improvement in health survey, 5 improved by ≥30% on low back function, and 8 reported that low back pain was more bothersome than stiffness, 6 of whom achieved the minimal clinically important difference for self-reported pain. Subgrouping of cases into structure-specific groups provided insight to different CME movement patterns. CONCLUSION: The use of CME assists in identifying atypical lumbar movement relative to an age and sex NRR. Data from this study, exemplified by representative case studies, provide preliminary evidence for distinct intervertebral disc, facet joint, and nerve root compression CME movement patterns in cases of chronic lumbar spondylosis.

The Role of Botulinum Toxin Type A in the Clinical Management of Refractory Anterior Knee Pain.

Anterior knee pain is a highly prevalent condition affecting largely young to middle aged adults. Symptoms can recur in more than two thirds of cases, often resulting in activity limitation and reduced participation in employment and recreational pursuits. Persistent anterior knee pain is difficult to treat and many individuals eventually consider a surgical intervention. Evidence for long term benefit of most conservative treatments or surgical approaches is currently lacking. Injection of Botulinum toxin type A to the distal region of vastus lateralis muscle causes a short term functional "denervation" which moderates the influence of vastus lateralis muscle on the knee extensor mechanism and increases the relative contribution of the vastus medialis muscle. Initial data suggest that, compared with other interventions for anterior knee pain, Botulinum toxin type A injection, in combination with an active exercise programme, can lead to sustained relief of symptoms, reduced health care utilisation and increased activity participation. The procedure is less invasive than surgical intervention, relatively easy to perform, and is time- and cost-effective. Further studies, including larger randomized placebo-controlled trials, are required to confirm the effectiveness of Botulinum toxin type A injection for anterior knee pain and to elaborate the possible mechanisms underpinning pain and symptom relief.

Nucleus pulposus deformation in response to rotation at L1-2 and L4-5.

BACKGROUND: Spinal rotation couples with lateral flexion as a composite movement. Few data report the in vivo mechanical deformation of the nucleus pulposus following sustained rotation. MRI provides a non-invasive method of examining nucleus pulposus deformation by mapping the hydration signal distribution within the intervertebral disc. METHODS: T1 weighted coronal and sagittal lumbar images and T2 weighted axial images at L1-2 and L4-5 were obtained from 10 asymptomatic subjects (mean age 29, range: 24-34 years) in sustained flexed and extended positions plus combined positions of left rotation with flexion and extension. Nucleus pulposus deformation was tracked by mapping the change in hydration profiles from coronal and sagittal pixel measurements. FINDINGS: An average sagittal change in position of 44° (SD 14.5°) from flexion to extension was recorded between L1 and S1 (range: 18°- 60°) resulting in a mean anterior nucleus pulposus deformation of 16% of disc hydration profile (range: 3.5%-19%) in 19/20 discs. When rotation was combined with either flexion or extension, mean coronal deformation was 4.8% (SD-5.1%; range: 0.4%-15%). Lateral nucleus pulposus deformation direction varied in rotation (44% deformed left and 56% deformed right). Intersegmental lateral flexion direction more strongly predicted nucleus pulposus deformation direction with 75% deforming contralaterally. INTERPRETATION: Nucleus pulposus deformation direction in young subjects was more predictable following sagittal position change than in rotation combined with flexion or extension. Deformation magnitude was reduced in rotated positions. Intersegmental lateral flexion was a stronger predictor of nucleus pulposus deformation direction.

Enduring efficacy of Botulinum toxin type A injection for refractory anterior knee pain.

PURPOSE: To examine long-term outcomes of Botulinum toxin type A (BoNT-A) injection to vastus lateralis (VL) for refractory anterior knee pain (AKP). METHODS: Two cohorts (private clinic referrals and previous research participants) injected with BoNT-A for AKP by one neurologist were surveyed retrospectively. Primary outcomes were self-reported benefit, duration of symptom relief, and knee surgery post-injection. Secondary outcomes were changes in utilization of medication/physiotherapy treatment, AKP symptoms and activity limitation. RESULTS: Overall, average symptom duration was 76 months (SD 98). Responses were available from 46 of 53 private patients. Thirty-eight reported benefit from injection, which was ongoing in 29. Average benefit was 25 months (SD 21). Nine individuals reported symptom recurrence after an average of 14 months (SD 21). Ten had knee surgery post-injection; six of whom had not benefitted from BoNT-A injection. Nineteen of 23 previous research participants were contactable. Initially, all responded favorably to injection. Symptomatic benefit, with an average duration of 44 months (SD 20), persisted in 15. Two subjects proceeded to surgical intervention. CONCLUSIONS: A single BoNT-A treatment to VL led initially to improved function and relief of knee-related symptoms in 57 of 65 individuals. Improvements were sustained at follow-up, with an average benefit of 34 months (SD 25) post-injection, in 44 of 57 cases.

Treatment of refractory anterior knee pain using botulinum toxin type A (Dysport) injection to the distal vastus lateralis muscle: a randomised placebo controlled crossover trial.

OBJECTIVES: This randomised controlled crossover trial examined the efficacy of botulinum toxin type A (BoNT-A) injection, plus an exercise programme, to remediate chronic anterior knee pain (AKP) associated with quadriceps muscle imbalance. METHODS: 24 individuals with refractory AKP received either BoNT-A (500 U Dysport) or the same volume saline injection to the vastus lateralis (VL) muscle and performed home exercises focusing on re-training the vastus medialis (VM) muscle. All subjects were offered open-label injection at 12 weeks. Knee-related disability (anterior knee pain scale; AKPS) and activity-induced pain (10 cm visual analogue scale) at 12 weeks were the primary outcomes. Peak isometric extensor force was recorded and normalised VL:VM ratios were derived from simultaneous surface electromyography. Self-reported pain and disability measures were collected at six time points to a mean of 20±8 months. RESULTS: 14 subjects received BoNT-A and 10 placebo injection. Improvement at 12 weeks was significantly greater for BoNT-A compared with placebo-injected subjects for the AKPS (p<0.03), pain on kneeling (p<0.004), squatting (p<0.02) and level walking (p<0.04). At week 12, five placebo subjects crossed over to open-label injection. At 24 weeks, 16 of 19 BoNT-A-injected and two of the remaining five placebo-injected subjects were either satisfied or very satisfied with treatment outcomes. Improvements were maintained in 11 of 14 BoNT-A-injected and two of five placebo subjects available at longer-term follow-up. CONCLUSION: BoNT-A injection produced a greater reduction in pain and disability than placebo injection in carefully selected patients with chronic AKP related to quadriceps muscle imbalance.

Nucleus pulposus deformation in response to lumbar spine lateral flexion: an in vivo MRI investigation.

Whilst there are numerous studies examining aspects of sagittal plane motion in the lumbar spine, few consider coronal plane range of motion and there are no in vivo reports of nucleus pulposus (NP) displacement in lateral flexion. This study quantified in vivo NP deformation in response to side flexion in healthy volunteers. Concomitant lateral flexion and axial rotation range were also examined to evaluate the direction and extent of NP deformation. Axial T2- and coronal T1-weighted magnetic resonance images (MRI) were obtained from 21 subjects (mean age, 24.8 years) from L1 to S1 in the neutral and left laterally flexed position. Images were evaluated for intersegmental ranges of lateral flexion and axial rotation. A novel methodology derived linear pixel samples across the width of the disc from T2 images, from which the magnitude and direction of displacement of the NP was determined. This profiling technique represented the relative hydration pattern within the disc. The NP was displaced away from the direction of lateral flexion in 95/105 discs (p < 0.001). The extent of NP displacement was associated strongly with lateral flexion at L2-3 (p < 0.01). The greatest range of lateral flexion occurred at L2-3, L3-4 and L4-5. Small intersegmental ranges of axial rotation occurred at all levels, but were not associated with NP displacement. The direction of NP deformation was highly predictable in laterally flexed healthy lumbar spines; however, the magnitude of displacement was not consistent with the degree of intersegmental lateral flexion or rotation.

Prolonged vastus lateralis denervation after botulinum toxin type A injection.

Intramuscular injection of botulinum toxin (BoNT) produces reversible blockade of neuromuscular transmission. In animal experimental models, recovery begins within four weeks and is usually complete by twelve weeks. We present evidence of prolonged denervation following BoNT injection of the vastus lateralis (VL) muscle to correct quadriceps muscle imbalance in patients with chronic anterior knee pain. Needle electromyography data were obtained from 10 subjects who had received a single BoNT treatment 5 to 19 months earlier as part of a clinical trial. Insertional and spontaneous activity, recruitment, and motor unit action potentials were examined. Clear differences between the injected and non-injected VL muscles, which correlated with the time since injection, were identified in all subjects. All 10 subjects studied with needle EMG showed evidence of persisting denervation in the BoNT-A injected VL muscle beyond the period of neuromotor recovery expected from animal experimental studies.

Assessment of osteoporotic fracture risk in community settings: a study of post-menopausal women in Australia.

The healthcare cost of managing osteoporotic fractures is projected to rise because of the change in population demographics. To reduce the fracture epidemic, strategies are needed to identify those at risk early to allow preventative intervention to be implemented. The aim of this study was to investigate if low-cost community-based assessments, such as calcaneal ultrasound and falls risk assessments, can discriminate a group of elderly women at risk of osteoporotic fracture from those at lower risk. Over the period of 2002-2003, 104 community-dwelling women (mean age 71.3, standard deviation 5.8) were recruited via various modes including advertisements in community newspaper and community centres. These women underwent dual-energy X-ray absorptiometry bone mineral density (BMD) and calcaneal quantitative ultrasound (QUS) measurements; spinal radiography; and performance-based assessment of strength, mobility and balance. The women were classified into a 'high risk' (osteoporotic) group, based on low BMD (T-score of

Clinical utility of calcaneal quantitative ultrasonometry and thoracic kyphosis assessments in identifying vertebral fractures in community settings.

OBJECTIVE: Individuals with existing vertebral fractures may not be aware that they are at high risk of subsequent fractures. We investigated if calcaneal quantitative ultrasonometry (QUS) and assessment of thoracic kyphosis could discriminate a group of older women with prevalent vertebral fracture from those without. METHODS: One hundred four women (mean age 71.3 +/- 5.8 yrs) underwent dual-energy x-ray absorptiometry (DEXA) bone mineral density (BMD; lumbar spine and hip), calcaneal QUS, and video rasterstereographic thoracic kyphosis measurements. They were dichotomized into a group with prevalent vertebral fracture (VF, n = 24) or without vertebral fracture (NVF, n = 80). RESULTS: Univariate variables associated with the VF group included broadband ultrasound attenuation (BUA; age-adjusted OR 1.96, 95% CI 1.12-3.42, p = 0.018); speed of sound (SOS; age-adjusted OR 2.01, 95% CI 1.09-3.70, p = 0.026); and thoracic kyphosis (age-adjusted OR 1.72, 95% CI 1.01-2.92, p = 0.049). A composite model (BUA and thoracic kyphosis) had higher area under the receiver-operating characteristic curve (AUC = 0.75) compared to lumbar spine DEXA BMD (AUC = 0.50, p = 0.0004) and total hip DEXA BMD (AUC = 0.60, p = 0.057). CONCLUSION: Reduced calcaneal QUS values and greater thoracic kyphosis were found to be significantly associated with the group of women with prevalent vertebral fractures. A composite risk score (BUA and thoracic kyphosis) had better discriminatory power than the individual risk factor of (low) DEXA BMD.

Analysis of dynamic angle of gait and radiographic features in subjects with hallux abducto valgus and hallux limitus.

BACKGROUND: Hallux abducto valgus and hallux limitus are two commonly encountered foot deformities causing altered structure and function of the first metatarsophalangeal joint and subsequent compensatory mechanisms. This study was undertaken to determine the relationships between these two deformities and transverse plane position of the foot, or angle of gait, and several radiographic angular and linear parameters with established reliability. METHODS: A convenience sample of 23 subjects with hallux abducto valgus, 22 subjects with hallux limitus, and 20 control subjects was used. Radiographic parameters were standardized weightbearing views and included lateral stressed dorsiflexion of the first metatarsophalangeal joint, composite, dorsoplantar, and lateral views. Angle of gait was obtained from powdered footprints recorded on paper. Two left and two right footprints identified on each trial were used to calculate angle of gait. RESULTS: The findings of the study suggest that an association between angle of gait and the presence of hallux abducto valgus or hallux limitus does not exist. Possible explanations may relate to the large variability of normal angle of gait, the need to identify factors extrinsic to the foot capable of affecting transverse plane orientation of the foot, and the addition of information relating to symptoms. CONCLUSIONS: In this study, the presence of hallux abducto valgus or hallux limitus did not correspond to an association with a particular angle of gait. Length and elevation of the first metatarsal were associated in subjects with hallux abducto valgus and hallux limitus.

Reliability and validity of the Hindi version of the Neck Pain and Disability Scale in cervical radiculopathy patients.

PURPOSE: To assess the reliability and validity of the Neck Pain and Disability Scale (NPAD) translated into Hindi. METHOD: Following a pilot study to ascertain uncertainties with existing terminology in the NPAD scale, a cervical radiculopathy patient cohort (n = 63) was assessed with the translated NPAD. Reliability was assessed by regression analysis for test-retest and by item-factor and factor-total score correlations. Face validity was compared in a cross-sectional design study with an asymptomatic group (n = 38). Convergent and divergent validity were investigated by correlating the NPAD scores with the Numerical Pain Rating Scale (NPRS) for neck and arm pain, and 10 cm long VAS Activity and VAS Depression scales. RESULTS: ICC values for test-retest NPAD total and factor scores were >0.92 and R2 values >0.912. Pearson product moment correlation of item vs. factor scores varied from 0.17 - 0.91 and for factor vs. total scores 0.72 - 0.91. Differences in NPAD scores between the patient and the asymptomatic group were significant (t = 30.90, p < 0.05). Convergent validity was explained when Factor 2 (minus item 20) was correlated (r = 0.67) with NPRS maximum value scores. Divergent validity was illustrated by low correlation with VAS Activity (r = 0.15) and negative correlation with VAS Depression (r = -0.80) scores. CONCLUSION: Based on the results of this study, the Hindi version of the NPAD is a reliable and valid instrument for the assessment of pain and disability in cervical radiculopathy patients.

An MRI investigation of intervertebral disc deformation in response to torsion.

BACKGROUND: The nucleus pulposus deforms towards an area of least compression in response to offset loading, however, there is a lack of data reporting the deformation patterns of nuclear material in rotated positions of the lumbar spine. Our purpose was to assess a novel methodology using MRI to track nuclear deformation in response to flexion and extension positions, and the combined positions of flexion with left rotation and extension with left rotation, at L1-2 and L4-5. METHODS: Three asymptomatic female subjects, mean age 27 years, underwent T2 weighted MRI sequences in flexed, extended, and left rotated positions combined with flexion and extension. A pixel profile technique was employed to determine direction and magnitude of nuclear deformation. RESULTS: In 5 of 6 discs examined, deformation of the nucleus occurred anteriorly in extension and posteriorly in flexion. Left rotation resulted in migration of nuclear material to the right in 9 of 12 discs. Of the three discs that demonstrated a right nuclear migration, two occurred at L4-5 and one at L1-2. INTERPRETATION: This methodology demonstrated that nucleus pulposus deformation can be measured reliably in various positions achieved within the confines of the MRI. The consistent migration of nuclear material following sagittal plane movement and the less consistent response to rotation positions suggest other asymmetrical loading on the intervertebral disc may accompany rotation.

Validation of the spin-T goniometer, a cervical range of motion device.

OBJECTIVE: To test the validity of the Spin-T goniometer for the assessment of cervical range of movement. METHODS: A linear regression analysis for paired neck movements using first a foam head model and then human subjects was performed to quantify the differences between the measurements obtained from the MotionStar, a movement-tracking device, and the Spin-T. A within-subject repeated measures design using simultaneous data acquisition was completed. RESULTS: The coefficient of determination (R2) for all planes of cervical range of motion for both model and human data sets was higher than 0.99. The regression equations for the model data showed no significant (P > .05) intercept for flexion-extension and lateral rotation. Human data showed statistically significant intercept for flexion-extension (mean, -0.52 degrees) and lateral flexion (mean, 0.81 degrees) at P < .05. CONCLUSION: This study quantifies the difference between the MotionStar and the Spin-T goniometer and documents the systematic error between the measures. Where the error reached statistical significance, the magnitude of the error was very small (< 1.5 degrees). The results of this study suggest that the Spin-T goniometer may be used as a valid measuring instrument for cervical range of movement.

Reliability of the spin-T cervical goniometer in measuring cervical range of motion in an asymptomatic Indian population.

OBJECTIVE: To examine the intratester reliability of the Spin-T goniometer, a cervical range of motion device, in a normal Indian population. METHODS: Subjects comprised 30 healthy adults with mean age of 34 years (range, 18-65 years). The subjects were stabilized in the sitting position and the Spin-T goniometer mounted on the head of the subject. The study design was a within-subject repeated intratester reliability trial conducted for cervical range of motion in 6 directions of movement. Three measurements were taken in each direction (flexion, extension lateral flexion, and lateral rotation) per participant. Reliability coefficients, intraclass correlation coefficients, and 95% confidence interval were derived from repeated-measures analysis of variance (ANOVA). Where differences in ANOVA were detected, a paired t test was conducted and the typical error values and coefficient of variance were calculated. RESULTS: All repeated measures showed high intraclass correlation coefficients (all >0.96, P < .01). The ANOVA detected no differences between trials for all movements except rotation. The typical error values for the rotation trials did not exceed 2.5 degrees and the coefficient of variance did not exceed 4%, which is clinically acceptable considering the normally variable cervical range of movement. CONCLUSION: In this study, the Spin-T goniometer proved to be a reliable measuring instrument for cervical range of movement in an Indian population. The use of a laser pointer fixed to the instrument ensured a consistent neutral start position.

Radiographic investigation of angular and linear measurements including first metatarsophalangeal joint dorsiflexion and rearfoot to forefoot axis angle.

This study investigated intra- and inter-rater reliability of several radiographic angular and linear parameters using 6 subjects. Using standard weight-bearing radiographs, the following measurements were performed: first metatarsal protrusion distance, hallux abductus, first intermetatarsal, calcaneal inclination and lateral intermetatarsal angles. Measurement of lateral stressed dorsiflexion of the first metatarsophalangeal joint and the rearfoot-to-forefoot-axis angle taken using a composite view were also obtained. All parameters were measured independently by 2 raters, and measurements were repeated on 3 separate occasions at weekly intervals. Intrarater reliability of radiographic measurements ranged between R = 0.65-1.00 for lateral stressed dorsiflexion, and between R = 0.91 and 0.99 for the rearfoot to forefoot axis angle. Inter-rater reliability of radiographic measurements ranged from R = 0.82-0.99. Specifically, lateral stressed dorsiflexion showed R = 0.87 with a mean difference of -1.47 (confidence interval [CI]: -3.42, 0.47), indicating no significant difference ( t = 1.54, P = 0.13). The rearfoot-to-forefoot-axis angle showed R = 0.92 with a mean difference of -0.15 (CI: -1.05, 0.74), indicating no significant difference ( t = 0.35, P = 0.73). The 7 angular and linear measurements chosen demonstrated high inter- and intrarater reliability. These results indicate that weight-bearing radiographic first metatarsophalangeal joint dorsiflexion using the lateral stressed dorsiflexion view, and measurement of the rearfoot-to-forefoot-axis angle using a composite view could be measured reliably within and between raters.

In vivo short-term precision of hip structure analysis variables in comparison with bone mineral density using paired dual-energy X-ray absorptiometry scans from multi-center clinical trials.

Hip structural analysis (HSA) is a technique for extracting strength-related structural dimensions of bone cross-sections from two-dimensional hip scan images acquired by dual energy X-ray absorptiometry (DXA) scanners. Heretofore the precision of the method has not been thoroughly tested in the clinical setting. Using paired scans from two large clinical trials involving a range of different DXA machines, this study reports the first precision analysis of HSA variables, in comparison with that of conventional bone mineral density (BMD) on the same scans. A key HSA variable, section modulus (Z), biomechanically indicative of bone strength during bending, had a short-term precision percentage coefficient of variation (CV%) in the femoral neck of 3.4-10.1%, depending on the manufacturer or model of the DXA equipment. Cross-sectional area (CSA), a determinant of bone strength during axial loading and closely aligned with conventional DXA bone mineral content, had a range of CV% from 2.8% to 7.9%. Poorer precision was associated with inadequate inclusion of the femoral shaft or femoral head in the DXA-scanned hip region. Precision of HSA-derived BMD varied between 2.4% and 6.4%. Precision of DXA manufacturer-derived BMD varied between 1.9% and 3.4%, arising from the larger analysis region of interest (ROI). The precision of HSA variables was not generally dependent on magnitude, subject height, weight, or conventional femoral neck densitometric variables. The generally poorer precision of key HSA variables in comparison with conventional DXA-derived BMD highlights the critical roles played by correct limb repositioning and choice of an adequate and appropriately positioned ROI.

Incidence of ankle contracture after moderate to severe acquired brain injury.

OBJECTIVE: To examine an adult population undergoing rehabilitation after brain injury to determine the incidence of ankle contracture and factors contributing to the development of this deformity. DESIGN: Descriptive study SETTING: Specialist inpatient neurosurgical rehabilitation unit in Australia. PARTICIPANTS: Patients (N=105) admitted with a new diagnosis of moderate to severe brain injury over a 12-month period. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Maximal ankle dorsiflexion range and the presence of abnormal muscle tone affecting the lower limb(s) were evaluated at weekly intervals. Ankle contracture was defined as maximal passive range of less than 0 degrees dorsiflexion with the knee in extension. Patients were grouped into 3 muscle tone categories: normal, predominantly spastic, or predominantly dystonic. Age, sex, mechanism and severity of brain injury, time to onset of ankle contracture, total length of hospital stay, and discharge mobility status data were also recorded. RESULTS: Muscle tone was designated as normal in 68 (64.7%), as spastic in 14 (13.3%), and as dystonic in 23 (21.9%) patients. The incidence of ankle contracture was 16.2% (17/105 cases). Ankle deformity correlated closely with muscle tone category. Of 23 cases with dystonic muscle overactivity, 17 developed contracture at some point between 1 and 16 weeks after brain injury, although no subject with normal tone or spasticity developed the deformity. There was a weak association between the severity of brain injury and development of ankle contracture. CONCLUSIONS: The incidence of ankle contracture was much lower than previously reported. Dystonic overactivity of the plantarflexor and invertor muscles is a major predisposing factor to ankle contracture.

Is there a difference in hip joint position sense between young and older groups?

BACKGROUND: Joint position sense (JPS) in the knee has been shown by many authors to decline with age. It has been speculated that this decrease contributes to abnormal joint mechanics during load-bearing activities and putatively results in joint degeneration. Surprisingly little research has been conducted on the human hip to determine benchmarks for normal JPS. METHOD: Fifty-nine community dwelling subjects, 30 young (mean age 21.7 years) and 29 older (mean age 75 years), were recruited to determine normal reference ranges for the effect of age on hip JPS. Active and passive repositioning tasks were performed in inner and outer ranges of the hip abduction plane of movement. An electromagnetic tracking system was used to obtain accurate error measurements of the angular displacement. RESULTS: Results indicated no difference in hip JPS between the young and older subjects (F(1,57) = 0.011, p = .917). However, it was found that for both age groups, accurate reproduction of position at the hip joint occurred in the inner range (F(1,57) = 13.760, p < .001). For both groups, active repositioning was more accurate than passive (F(1,57) = 9.265, p = .004). CONCLUSIONS: In this study, no difference in hip JPS was found between young and older subjects. Accuracy was greater in the inner range, with active repositioning demonstrating higher precision compared to passive repositioning of the limb.