Search PubMed⌕ Search

Biomedical subjects

M E Morris

Publications and source records attributed to M E Morris.

At least 19 recordsLinked to original sources
PubMed2006

Kinematic patterns associated with accuracy of the drop punt kick in Australian Football.

Research into the kinematics of movement associated with the accuracy of the drop punt kick in Australian Football has been limited. The aim of this study was to examine pelvic and lower limb kinematics during the performance of a drop punt kick, in order to identify factors associated with accurate kicking performance. Ten professional Australian Football League (AFL) players performed 20 drop punt kicks towards a target situated 15m away, using their preferred leg. A three-dimensional motion analysis system was used to record the kicking motion from heel contact of the support limb through to ball contact. The subjects were divided into an accurate group (> or =50% accuracy; n=5) and an inaccurate group (<50% accuracy; n=5) based on target hit rate. Kinematic profiles for both kicking and support limbs were compared between the two groups. Results showed that the accurate group had significantly greater hip flexion in both limbs and greater knee flexion in the support limb throughout the kicking movement. The accurate group also had significantly greater anterior pelvic tilt at heel contact (accurate 20.8 degrees ; inaccurate 12.7 degrees ). These data show that kinematic differences in lower limb joint angles may be related to kicking accuracy.

Adult↗
PubMed2006

Foot rotation--a potential target to modify the knee adduction moment.

Isolating the particular joints/limb segments associated with knee adductor moment variability may provide clinically important data that could help to identify strategies to reduce medial tibiofemoral joint load. The aim of this study was to examine whether or not foot and thigh rotation during human locomotion are significant determinants of knee adductor moment variability. Three-dimensional gait analyses were performed on 32 healthy adult women (mean age 54+/-12 years, mean BMI 25+/-4 kg m(-2)) with radiologically normal knees. The relationships between foot rotation, thigh rotation and the external knee adduction moment were examined during early and late-stance phases of the gait cycle. The degree of foot rotation correlated significantly with the magnitude of the peak knee adduction moment during late stance (r=0.40, p=0.024). No significant associations were apparent between thigh rotation and the peak knee adduction moment. The association between foot rotation and the knee adduction moment in this study suggests that women who walk with external rotation at the foot reduce their knee adduction moment during late stance. This result implies that changes in foot kinematics can modify the medial tibiofemoral load during gait, which may be important in the prevention and management of knee osteoarthritis.

Adult↗
PubMed2006

Sagittal plane movement at the tibiofemoral joint influences patellofemoral joint structure in healthy adult women.

OBJECTIVES: The influence exerted on cartilage and bone volumes by locomotor patterns is poorly understood, particularly at the patellofemoral joint. The aim of this study was to investigate the relationship between sagittal plane movement at the tibiofemoral joint and patella cartilage and bone volumes during the locomotion of healthy adult females. METHODS: Three-dimensional Vicon gait analyses and magnetic resonance imaging were performed on 20 healthy adult women. The relationships between the degree of tibiofemoral flexion and extension at varying stages of the gait cycle and the concomitant medial, lateral and total patella cartilage and total bone volumes were examined. RESULTS: For every degree the knee flexed during mid-stance, there was a 62.8 microL (95% confidence interval 3.7-122.0) increase in the medial patella facet cartilage volume after adjustment for age and the body mass index (BMI) (P = 0.04). A similar relationship that approached significance was observed for the lateral patella facet cartilage volume after adjustment for age and the BMI (P = 0.08). No association was observed between the sagittal plane tibiofemoral movements and the patella bone volume. CONCLUSIONS: The association between patella cartilage volume and tibiofemoral knee movement suggests that for every degree increase in knee flexion during mid-stance, there is an associated increase in patella cartilage volume. This may be the result of the geometry of the femoral condyle influencing patella tracking and or the retropatellar load exerted on the patella during walking. These results may have important implications for people who hyperextend their knee during gait and the pathogenesis of patellofemoral osteoarthritis.

Age Factors↗
PubMed2006

Clinician agreement on gait pattern ratings in children with spastic hemiplegia.

The level of agreement between clinicians' ratings of gait patterns in children with spastic hemiplegia was investigated using the Winters, Gage, and Hicks (WGH) classification scale. Sixteen clinicians (nine physiotherapists, seven orthopaedic surgeons) from six gait laboratories in five different countries rated gait patterns in 34 children with spastic hemiplegia (22 males, 12 females; mean age 10y [SD 3y], range 6-18y). Archived three-dimensional gait reports (kinematic and video data) and videos (video clips only) were rated for each child. Agreement between clinicians was substantial for reports (weighted kappa [wkappa] 0.77, range 0.62-0.89). Agreement was lower for videos (wkappa 0.63, range 0.39-0.97) and for clinicians' agreement between reports and corresponding videos (wkappa 0.62, range 0.47-0.76). Exact agreement was unacceptable for some gait patterns using reports (mean 65%, range 32-74%) and videos (mean 53%, range 35-94%). Not all gait patterns could be rated using the original WGH categories. It was concluded that: (1) agreement is acceptable using the WGH tool; (2) kinematic data from 3D instrumented gait analysis and video should be used together when using the WGH scale; and (3) further refinement of this classification is required.

Adolescent↗
PubMed2005

The high-level mobility assessment tool (HiMAT) for traumatic brain injury. Part 1: Item generation.

PRIMARY OBJECTIVE: To generate a comprehensive list of items for a scale suitable for assessing high-level mobility in people with traumatic brain injury (TBI). RESEARCH DESIGN: High-level mobility items were generated following a critical evaluation of existing adult and paediatric mobility scales and by surveying expert clinicians for opinions about items appropriate for inclusion on a high-level mobility scale. MAIN OUTCOMES AND RESULTS: The critical evaluation identified 18 different items from 31 mobility scales. These included nine walking items in addition to higher level activities such as stair use, running, jumping and hopping. Expert clinicians generated 157 items that were collated and condensed to 88 items for ranking on a questionnaire. Fifteen items on the questionnaire were rated as very important by 80% of the expert clinicians. These included walking forwards, walking on slopes and different surfaces, changing direction, walking long distances and stair use. Running items included forwards, backwards, on slopes and over different surfaces, changing direction, stopping and starting as well as running long distances. Balancing in single limb stance was also included. CONCLUSION: The final list comprised walking, running, hopping, skipping, jumping and balance items. This initial version of the HiMAT has face and content validity although requires further testing to investigate whether it is uni-dimensional and valid for people with TBI.

Activities of Daily Living↗
PubMed2005

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.

Adult↗
PubMed2005

High reproducibility of patellar tendon vascularity assessed by colour Doppler ultrasonography: a reliable measurement tool for quantifying tendon pathology.

BACKGROUND: This study examined whether patellar tendon vascularity could be quantified accurately in the clinical setting using colour Doppler ultrasonography. METHODS: A sonographer and two radiologists visually estimated tendon vascularity in millimetres in 74 tendons during ultrasound (US) examination and from hard copy films. These estimates were then compared to the length of vessels measured from the digital image in millimetres and the correlation between them was determined. A subset of 16 tendons was used to compare the estimates of vascularity by two examiners at US examination. RESULTS: The estimation of vascular length at US examination correlated highly with the measured vascular length (r = 0.92; 95% confidence interval (CI) 0.87 to 0.94), as did the length estimated from the films (r = 0.94; 95% CI 0.9 to 0.96). The correlation between examiners was 0.84 (95% CI 0.51 to 0.94) for the estimates made during US examination and 0.85 (95% CI 0.59 to 0.95) for the vessel lengths measured from the digital images. CONCLUSIONS: These excellent correlations indicate that tendon vascularity can be reliably estimated using colour Doppler ultrasonography and tendon vascularity could therefore be used by clinicians to rate clinical change. This method of quantifying tendon vascularity could also be used in research to investigate the effects of tendon treatments on vascularity.

Humans↗
PubMed2005

Multilevel orthopaedic surgery in group IV spastic hemiplegia.

Most children with spastic hemiplegia have high levels of function and independence but fixed deformities and gait abnormalities are common. The classification proposed by Winters et al is widely used to interpret hemiplegic gait patterns and plan intervention. However, this classification is based on sagittal kinematics and fails to consider important abnormalities in the transverse plane. Using three-dimensional gait analysis, we studied the incidence of transverse-plane deformity and gait abnormality in 17 children with group IV hemiplegia according to Winters et al before and after multilevel orthopaedic surgery. We found that internal rotation of the hip and pelvic retraction were consistent abnormalities of gait in group-IV hemiplegia. A programme of multilevel surgery resulted in predictable improvement in gait and posture, including pelvic retraction. In group IV hemiplegia pelvic retraction appeared in part to be a compensating mechanism to control foot progression in the presence of medial femoral torsion. Correction of this torsion can improve gait symmetry and function.

Adolescent↗
PubMed2004

Reviewing knee osteoarthritis--a biomechanical perspective.

Osteoarthritis (OA) is the most common form of arthritis and is a major cause of disability in people aged over 65. Despite the major socioeconomic burden imposed by OA, the aetiology of this condition remains unclear. Although controversial, several metabolic factors have been implicated in the disease pathogenesis. Nevertheless, no unequivocal systemic risk factors for the onset or progression of OA have been identified. Recently, there has been a growing interest in the biomechanical factors associated with the pathogenesis of OA. This review aims to discuss several of the more pertinent biomechanical and neuromuscular factors, such as the knee adduction moment and muscle strength, that are becoming increasingly accepted as factors that contribute toward the pathogenesis of knee OA.

Biomechanical Phenomena↗
PubMed2003

The effect of the knee adduction moment on tibial cartilage volume and bone size in healthy women.

OBJECTIVES: There is considerable evidence that an abnormally high knee adductor moment is a characteristic of the gait patterns in people with knee osteoarthritis (OA). The aim of this study was to examine the relationship between the peak knee adduction moment during the early and late stance phases of gait, and medial and lateral tibial bone size and cartilage volume in healthy women. METHODS: Three-dimensional Vicon gait analyses and magnetic resonance imaging (MRI) were performed on 20 healthy women without knee OA. The external knee adduction moment was correlated with medial and lateral tibial bone size and cartilage volume for the dominant leg. RESULTS: The knee adduction moment significantly correlated with the bone size of the medial tibial plateau (r = 0.63, P < 0.005), but was not related to the bone size of the lateral plateau. No relationship was observed between the knee adduction moment and medial or lateral tibial cartilage volume. CONCLUSIONS: Although the knee adduction moment was positively associated with the bone size of the medial tibial plateau, it appeared to have little effect on cartilage volume in that compartment in healthy women. It may be that the effect of the knee adduction moment differs in healthy subjects compared with those with established knee OA.

Aged↗
PubMed2003

Reconstructive neurosurgery for Parkinson's disease: a systematic review and preliminary meta-analysis.

This systematic review and meta-analysis aimed to identify the determinants for best practice and establish current benchmarks for recovery following reconstructive neurosurgery for people with Parkinson's disease. Eleven studies reporting results for 95 grafted patients were selected on the grounds of using optimal surgical techniques and the Core Assessment Program for Intracerebral Transplantation (CAPIT) protocol for data collection. Consistent trends demonstrating high levels of recovery were identified on most outcome measures. Determinants for best practice were identified as selecting younger patients; using low dose immunosuppression; bilateral grafting; and employing strategies to ensure the quantity and viability of the grafted cells. Secondary analysis of data demonstrated a correlation of rho=0.666 (P<0.05) between increases in striatal dopaminergic activity and UPDRS Motor (off) scores. Overall effect size 'd' was found to be 1.129 UPDRS Motor (off) condition and 0.719 for UPDRS Total (off) condition. The design of the studies and the variable standards for reporting the data precluded the use of more powerful and accurate meta-analyses. It was recommended that the creation of a collaborative database would improve the extraction of data and allow for more powerful statistical analyses for evaluating the overall harm and benefits associated with reconstructive neurosurgery.

Brain Tissue Transplantation↗
PubMed2002

Changes in gait and fatigue from morning to afternoon in people with multiple sclerosis.

OBJECTIVES: The aim was to measure changes in walking patterns and self rated fatigue in people with multiple sclerosis (MS) compared with age matched control subjects, from the morning to the afternoon within a single day. METHODS: Fourteen patients with MS and the same number of matched control subjects performed four 10 m gait trials at their preferred walking speed at 10 00 am and then again at 3 00 pm on the same day. Gait speed, stride length, cadence, and the percentage of the gait cycle spent in double limb support were measured using a foot switch stride analyzer. Patients with MS also self rated their fatigue levels in the morning and afternoon using an 11 point scale. RESULTS: Compared with control subjects, patients walked very slowly, with reduced stride length and around twice as much variability in gait performance. Although self rated fatigue significantly increased from the morning to the afternoon, walking patterns remained consistent in both groups over the course of the day. CONCLUSIONS: These findings imply that mechanisms controlling locomotion are separate from those regulating perceived fatigue. Objective measures of performance, rather than self report, should be used to monitor change in patients with multiple sclerosis.

Adult↗
PubMed2001

The biomechanics and motor control of gait in Parkinson disease.

Parkinson disease is a progressive neurological condition characterised by hypokinesia (reduced movement), akinesia (absent movement), tremor, rigidity and postural instability. These movement disorders are associated with a slow short-stepped, shuffling gait pattern. Analysis of the biomechanics of gait in response to medication, visual cues, attentional strategies and neurosurgery provides insight into the nature of the motor control deficit in Parkinson disease and the efficacy of current therapeutic interventions. In this article we supplement a critical evaluation of the Parkinson disease gait literature with two case examples. The first case describes the kinematic gait response of an individual with Parkinson disease to visual cues in the "off" phase of the levodopa medication cycle. The second case investigates the biomechanics and motor control of turning during walking in a patient with Parkinson disease compared with elderly and young control subjects. The results are interpreted in light of the need for gait analysis to investigate complex functional walking tasks rather than confining assessment to straight line walking, which has been the trend to date.

Biomechanical Phenomena↗
PubMed2001

Management of upper limb dysfunction in children with cerebral palsy: a systematic review.

Effective use of the upper limb can impact on educational outcomes, participation in activities of daily living and vocational options for many children with cerebral palsy (CP). This article presents the results of a systematic review of the literature on the management of upper limb dysfunction in children with CP. The range of management options includes therapies such as physiotherapy, occupational therapy, neurodevelopmental therapy and conductive education; peripheral splinting and casting; focal or generalized pharmacotherapy; and surgery to improve upper limb function or correct deformity. A literature search identified 60 papers, of which four were randomized controlled trials and 44 were prospective studies with objective outcome measures. Principal studies undertaken for each type of treatment and the efficacy of the different types of treatment were critically evaluated. In addition, the current level of evidence for each study was evaluated according to Sackett's (1989) model and ICIDH-2 classification. A close examination of two relatively new treatments for upper limb spasticity, constraint induced movement therapy and botulinum toxin type A (BTX-A) was conducted with reference to more extensive data on the efficacy of BTX-A in the lower limb.

Botulinum Toxins, Type A↗
PubMed2001

Reliability of measurements obtained with the Timed "Up & Go" test in people with Parkinson disease.

BACKGROUND AND PURPOSE: The Timed "Up & Go" Test (TUG) is used to measure the ability of patients to perform sequential locomotor tasks that incorporate walking and turning. This study investigated the retest reliability, interrater reliability, and sensitivity of scores obtained with the TUG in detecting changes in mobility in subjects with idiopathic Parkinson disease (PD). SUBJECTS: The performance of 12 people with PD was compared with that of 12 age-matched comparison subjects without PD. METHODS: The subjects with PD completed 5 trials of the TUG after withdrawal of levodopa for 12 hours ("off" phase of the medication cycle) as well as an additional 5 trials 1 hour after levodopa was administered ("on" phase of the medication cycle). They were scored on the Modified Webster Scale at both sessions. The comparison subjects also performed 5 TUG trials. All trials were videotaped and timed by 2 experienced raters. The videotape was later rated by 3 experienced clinicians and 3 inexperienced clinicians. RESULTS: For the subjects with PD, within-session performance was highly consistent, with correlations (r) ranging from.80 to.98 for the "off" phase and from.73 to.99 for the "on" phase. The performance of the comparison subjects across the 5 trials was also highly consistent (r=.90-.97). Comparisons showed differences between trials 1 and 2 on the TUG for both groups. Removal of data for trial 1 (the practice trial) further enhanced retest reliability. There was close agreement in TUG scores among raters despite different levels of experience (intraclass correlation coefficient [3,1]=.87-.99). Mean TUG scores were different between the "on" and "off" phases of the levodopa cycle and between subjects with PD and comparison subjects during the "on" phase. CONCLUSION AND DISCUSSION: Retest reliability and interrater reliability of the TUG measurements were high, and the measurements reflected changes in performance according to levodopa use. The TUG can also be used to detect differences in performance between people with PD and elderly people without PD.

Activities of Daily Living↗