Anna H. Mackey
University of Auckland
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Anna H. Mackey.
Developmental Medicine & Child Neurology | 2003
Anna H. Mackey; Glenis Lobb; Sharon Walt; N. Susan Stott
The aim of this study was to establish the reliability and validity of visual gait assessment in children with spastic diplegia, who were community or household ambulators, using a modified version of the Physicians Rating Scale, known as the Observational Gait Scale (OGS). Two clinicians viewed edited split-screen video recordings of 20 children/adolescents (11 males, 9 females; mean age 12 years, range 6 to 21 years) made at the time of three-dimensional gait analysis (3-DGA). Walking ability in each child was scored at initial assessment and reassessed from the same videos three months later using the first seven sections of the OGS. Validity of the OGS score was determined by comparison with 3-DGA. The OGS was found to have acceptable interrater and intrarater reliability for knee and foot position in mid-stance, initial foot contact, and heel rise with weighted kappas (wk) ranging from 0.53 to 0.91 (intrarater) and 0.43 to 0.86 (interrater). Comparison with 3-DGA suggests that these sections might also have high validity(wk range 0.38-0.94). Base of support and hind foot position had lower interrater and intrarater reliabilities (wk 0.29 to 0.71 and wk 0.30 to 0.78 respectively) and were not easily validated by 3-DGA.
Developmental Medicine & Child Neurology | 2004
Anna H. Mackey; Sharon Walt; Glenis Lobb; N. Susan Stott
This study investigated the reliability of the modified Tardieu scale in the assessment of biceps spasticity in the upper limbs of children with hemiplegic cerebral palsy (CP). Ten children, with hemiplegic CP participated in the study: six males (mean age 9 years, SD 4 years) and four females (mean age 12 years, SD 3 years). Blinded, duplicate measures of dynamic elbow extension were performed on the hemiplegic arm at time 0 and 7 days later, using the three angular velocities described in the Tardieu scale (V1, slow; V2, speed of gravity; V3, as fast as possible). The resulting elbow joint angles were defined as R1, the angle of catch following a fast velocity stretch at either V2 or V3; and R2, the passive range of movement achieved following a slow velocity stretch at V1. Both elbow joint angle and movement angular velocity were measured by three‐dimensional kinematics. Median error in measured elbow joint angle within one session ranged from 3 to 5°. Between sessions median absolute differences in measured elbow joint angle ranged from 4 to 13°, with measurement errors of up to 25 to 30° in some participants at the fastest velocity (V3). The therapist was able to apply three significantly different angular velocities as required for the Tardieu scale (p < 0.001). However, the ranges of the three angular velocities overlapped, with fast velocities for some participants being equivalent to slow velocities for other participants. Three out of 10 participants had an intersessional difference in their R2‐R1 score of more than 20°. From this study, we concluded that the R2‐R1 value determined from the modified Tardieu scale may be of limited value in assessing biceps spasticity the upper limbs in children with hemiplegic CP.
Frontiers in Neurology | 2014
Anna H. Mackey; Cathy M. Stinear; Susan Stott; Winston D. Byblow
Aim: To explore the relationship between motor cortical and descending motor pathway reorganization, lesion type, and upper limb function in youth with unilateral cerebral palsy (CP). Methods: Twenty participants with unilateral CP (mean age 15 ± 3 years; 11 males) completed a range of upper limb functional measures. Structural MRI, diffusion-weighted, and functional MRI were conducted to determine type and extent of brain lesion, descending white matter integrity, and whole-brain activity during affected hand use. Single pulse transcranial magnetic stimulation (TMS) (n = 12) was used to examine functional integrity of the corticospinal pathway as well as primary motor cortex intracortical and interhemispheric inhibition from motor-evoked potentials and silent periods. Results: Fractional anisotropy measures within the posterior limb of the internal capsule were a predictor of upper limb function (R2 = 0.41, F = 11.3, p = 0.004). Participants with periventricular lesions tended to have better upper limb function [F(2, 17) = 42.48, p < 0.0001]. Five participants with evidence of cortical reorganization and functional ipsilateral projections to their affected hand had worse upper limb function. Deficits in intracortical and interhemispheric inhibitory mechanisms were found in participants with worse upper limb function (Melbourne Assessment of Unilateral Upper Limb Function: Mann Whitney p = 0.02). Conclusion: Neuroimaging and TMS can provide useful information related to hand function of individuals with unilateral CP and may have potential to assist as a predictive tool and/or guide rehabilitation.
Gait & Posture | 2008
Anna H. Mackey; Ngaire Stott; Sharon Walt
This study evaluated within- and between-session reliability and validity of temporal-spatial gait parameters derived from the intelligent device for energy expenditure and activity (IDEEA) activity monitor (Minisun, Fresno, CA) in subjects with cerebral palsy, using three-dimensional gait analysis (3-DGA) as the criterion standard. Twenty-five subjects with cerebral palsy (mean age 14.1 years, range 8-23) and 30 control subjects (mean age 14.2 years, range 7-24) completed two 3-DGA, 1 week apart with simultaneous IDEEA data collection. The IDEEA had lower within-session reliability than the 3-DGA for both groups, indicated by greater measurement errors and wider repeatability values for all temporal-spatial parameters. Between-session reliability of 3-DGA was high for both groups with intra-class correlation coefficients (ICC) >0.80. The IDEEA monitor showed high between-session reliability for control subjects (ICC 0.71-0.89), but lower reliability in subjects with cerebral palsy, particularly for walking velocity and stride length (ICC 0.53 and 0.62, respectively). Validity comparison between IDEEA and 3-DGA measures using Bland Altman 95% limits of agreement showed a measurement bias, with the IDEEA over-estimating step and stride length and underestimating cadence in both subject groups compared to 3-DGA. The 95% limits of agreement were smaller in controls (step +/-0.20 m; stride +/-0.27 m; walking velocity +/-0.28 m/s) than in subjects with cerebral palsy (step +/-0.36 m; stride +/-0.37 m; velocity +/-0.58 m/s). Modifications may be necessary to improve the reliability and validity of the IDEEA in children, particularly for use in neurological conditions.
Archives of Physical Medicine and Rehabilitation | 2009
Anna H. Mackey; Penelope Hewart; Sharon Walt; N. Susan Stott
OBJECTIVE To evaluate the sensitivity and specificity of the Intelligent Device for Energy Expenditure and Activity (IDEEA) monitor in detecting functional activities in young people with cerebral palsy (CP). DESIGN Validation study. SETTING Two identical data collections completed 1 week apart at a gait laboratory. PARTICIPANTS Twenty-five young people with CP and 30 able-bodied (AB) peers (age 8-25 y; mean age CP 14.1 y, Gross Motor Function Classification System Level I-III; mean age AB, 14.2 y). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Each participant completed 5 functional activities (sitting, lying, standing, walking, and stairs), with the monitor attached. The sensitivity and specificity of the monitor in detecting each activity was calculated by comparison to a written timed report. RESULTS Sitting, lying, and standing were detected with median 100% sensitivity in both participant groups and across both testing sessions. Accuracy of walking detection was reduced compared with static activities (P<.05) across the 2 sessions and groups. The CP group had a significantly higher number of participants where the activity was not detected with 100% sensitivity (lie: 18% CP, 5% AB, P<.04; stand: 12% CP, 0% AB, P<.02; walk: 96% CP, 81% AB, P<.03). Stair climbing was detected in only half of the 12 participants with CP who could achieve the task. The IDEEA demonstrated high specificity (range, 97%-100%) for both participant groups. CONCLUSIONS The IDEEA activity monitor had high levels of sensitivity and specificity in determining everyday static activities in participants with CP, with greater difficulties in detecting dynamic activities of walking and stair climbing.
European Journal of Neurology | 2008
Anna H. Mackey; F Miller; Sharon Walt; Mc Waugh; Ngaire Stott
Background and purpose: To examine whether three‐dimensional (3‐D) kinematic analysis can detect changes in upper limb tasks (reach and hand‐to‐mouth) in children with hemiplegia, following upper limb botulinum toxin A injections.
Journal of Paediatrics and Child Health | 2010
Nicole Vogts; Anna H. Mackey; Shanthi Ameratunga; N. Susan Stott
Aim: To pilot the use of the Craig Hospital Inventory of Environmental Factors (CHIEF) questionnaire to ascertain information regarding barriers to participation experienced by a sample of New Zealand children with cerebral palsy.
Health Psychology | 2013
Jimmy Chong; Anna H. Mackey; N. Susan Stott; Elizabeth Broadbent
OBJECTIVES To investigate whether drawings of the self walking by children with cerebral palsy (CP) were associated with walking ability and illness perceptions. METHOD This was an exploratory study in 52 children with CP (M:F = 28:24), mean age 11.1 years (range 5-18), who were attending tertiary level outpatient clinics. Children were asked to draw a picture of themselves walking. Drawing size and content was used to investigate associations with clinical walk tests and childrens own perceptions of their CP assessed using a CP version of the Brief Illness Perception Questionnaire. RESULTS Larger drawings of the self were associated with less distance traveled, higher emotional responses to CP, and lower perceptions of pain or discomfort, independent of age. A larger self-to-overall drawing height ratio was related to walking less distance. Drawings of the self confined within buildings and the absence of other figures were also associated with reduced walking ability. CONCLUSION Drawing size and content can reflect walking ability, as well as symptom perceptions and distress. Drawings may be useful for clinicians to use with children with cerebral palsy to aid discussion about their condition.
Physiotherapy | 2003
Anna H. Mackey; Sharon Walt; N. Susan Stott
Summary Botulinum toxin type A has recently become a treatment option in the management of spasticity in children with cerebral palsy. Intramuscular injections of botulinum toxin A block the release of acetylcholine at the motor end plate, leading to reversible chemodenervation of muscle. This has been shown to provide a clinically useful reduction in localised spasticity for 12-16 weeks with flow-on into more long-term improvements in function in about 5% of children (termed golden responders). This review discusses the role of botulinum toxin A in the management of spasticity in children with cerebral palsy, to help therapists to select appropriate patients and maximise the potential gains from botulinum toxin A treatment.
Journal of Pediatric Orthopaedics B | 2014
Shiran Zhang; Nichola C. Wilson; Anna H. Mackey; Ngaire Stott
Hip subluxation is common in children with cerebral palsy (CP). The aim of this study was to describe the radiological outcome of reconstructive hip surgery in children with CP, gross motor function classification system (GMFCS) level IV and V, and determine whether the GMFCS level plays a predictive role in outcome. This was a retrospective cohort study conducted at a tertiary-level pediatric hospital with a CP hip surveillance program. Of 110 children with GMFCS IV and V CP registered for hip surveillance, 45 underwent reconstructive hip surgery between 1997 and 2009, defined as varus derotational proximal femoral osteotomy with or without additional pelvic osteotomy. Eleven children were excluded because of lack of 12-month follow-up (n=10) or missing clinical records (n=1). Thus, 21 GMFCS IV children (median age 6 years at surgery) and 13 GMFCS V children (median age 5 years at surgery), who underwent 58 index surgeries, were included in the study. Clinical records and radiology were reviewed. The two surgical groups were femoral osteotomy (varus derotational femoral osteotomy with an AO blade plate or femoral locking plate fixation), or femoral ostetotomy with additional pelvic osteotomy. Reimer’s migration percentage (MP) was calculated from anteroposterior pelvis radiographs to determine the outcome for each hip independently. Failure was defined as MP of greater than 60% or further operation on the hip. Reconstructive surgeries were performed for 58 hips with a median preoperative MP of 55%. There were 15 failures at a median of 62 months, including nine failures in 35 GMFCS IV hips and six failures in 23 GMFCS V hips. Overall, GMFCS V hips tended to fail earlier, (hazard ratio 2.3) with a median time to failure of 78 and 39 months for GMFCS IV and V hips, respectively. Combined femoral and pelvic osteotomies had the lowest failure rates in both groups of patients. The GMFCS classification may have some predictive value for outcomes following reconstructive hip surgery, with surgery for GMFCS V hips tending to fail earlier.