Motor performance after treatment of pilocytic astrocytoma in the posterior fossa in childhood.

BACKGROUND: Pilocytic astrocytoma is the most common brain tumour type in childhood located in the posterior fossa, and treated mainly with surgery. These tumours have low mortality, but knowledge concerning its long-term outcome is sparse. AIMS: The aim was to investigate if patients treated for pilocytic astrocytoma in the posterior fossa had motor complications, including balance, motor and process skills. METHODS AND RESULTS: This descriptive single-centre study includes eight children and 12 adults, treated for pilocytic astrocytoma as children. Motor performance was investigated with Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, and dynamic balance with the mini-balance evaluation systems test. Physiological cost index, six-minute walk test, hand grip strength and assessment of motor and process skills were also evaluated. Ten patients reported motor difficulties, mainly from the upper limbs. The motor performance test showed results within normal limits except for manual dexterity, which was significantly below mean (p = .008). In the dynamic balance test patients had significantly lower results compared with controls (p = .036). Physiological cost index, six-minute walk tests and hand grip strength showed results within normal limits. In the Assessment of Motor and Process Skills, patients over 16 years had significantly lower results compared with test norms for motor activities of daily living (ADL) and 30% of all patients scored below the cut-off level for difficulties with motor skills. CONCLUSIONS: Motor performance for patients treated for pilocytic astrocytoma in the posterior fossa in childhood is satisfactory but some patients display difficulties with balance, manual dexterity and ADL motor skills. Thus, it is important to identify those in need of motor follow-up and training.

Inclination angles of the ankle and head relative to the centre of mass identify gait deviations post-stroke.

BACKGROUND: Whole-body movement adjustments during gait are common post-stroke, but comprehensive ways of quantifying and evaluating gait from a whole-body perspective are lacking. RESEARCH QUESTION: Can novel kinematic variables related to Center of Mass (CoM) position discriminate side asymmetries as well as coordination between the upper and lower body during gait within persons post-stroke and compared to non-disabled controls? METHODS: Thirty-one persons post-stroke and 41 age-matched non-disabled controls walking at their self-selected speed were recorded by 3D motion capture. The Ankle-CoM Inclination Angle (A-CoMIA) and the Head-CoM Inclination Angle (H-CoMIA) defined the angle between the CoM and the ankle and the head, respectively, in the frontal plane. These angles and their angular velocities were compared between groups, and with regard to motor impairment severity during all phases of the gait cycle (GC) using a functional interval-wise testing analysis suitable for curve data. Upper and lower body coordination was assessed using cross- correlation. RESULTS: The A-CoMIA was symmetrical between body sides in persons post-stroke but larger compared to controls. The angular velocity of A-CoMIA also differed when compared to controls. The H-CoMIA was consistently asymmetrical in persons post-stroke and larger than in controls throughout the stance phase. There were only minor group differences in the angular velocity of H-CoMIA, with some side asymmetry in persons post-stroke. The A-CoMIA of the non-affected side, and the H- CoMIA, discriminated between persons with more severe impairments compared to those with milder impairments post-stroke. The variables showed strong cross- correlations in both groups. SIGNIFICANCE: The A-CoMIA and Head-CoMIA discriminated post-stroke gait from non-disabled, as well as motor impairment severity. These variables with the advantageous curve analysis during the entire GC add valuable whole-body information to existing parameters of post-stroke gait analysis through assessment of symmetry and upper and lower body coordination.

Temporal coordination of the sit-to-walk task in subjects with stroke and in controls.

OBJECTIVES: To explore events and describe phases for temporal coordination of the sit-to-walk (STW) task, within a semistandardized set up, in subjects with stroke and matched controls. In addition, to assess variability of STW phase duration and to compare the relative duration of STW phases between the 2 groups. DESIGN: Cross-sectional. SETTING: Research laboratory. PARTICIPANTS: A convenience sample of persons with hemiparesis (n=10; age 50-67y) more than 6 months after stroke and 10 controls matched for sex, age, height, and body mass index. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Relative duration of STW phases, SE of measurement in percentage of the mean, and intraclass correlation coefficients (ICCs). RESULTS: Four STW phases were defined: rise preparation, transition, primary gait initiation, and secondary gait initiation. The subjects with stroke needed 54% more time to complete the STW task than the controls did. ICCs ranged from .38 to .66 and .22 to .57 in the stroke and control groups, respectively. SEs of measurement in percentage of the mean values were high, particularly in the transition phase: 54.1% (stroke) and 50.4% (controls). The generalized linear model demonstrated that the relative duration of the transition phase was significantly longer in the stroke group. CONCLUSIONS: The present results extend existing knowledge by presenting 4 new phases of temporal coordination of STW, within a semistandardized set-up, in persons with stroke and in controls. The high degree of variability regarding relative STW phase duration was probably a result of both the semistandardized set up and biological variability. The significant difference in the transition phase across the 2 groups requires further study.

The Arm Posture Score for assessing arm swing during gait: an evaluation of adding rotational components and the effect of different gait speeds.

In 3D gait analysis, quantification of leg movements is well established, whereas a measure of arm swing has been lacking. Recently, the Arm Posture Score (APS) was introduced to characterize arm movements in children with cerebral palsy, including information from four variables (APS4) in the sagittal and frontal planes. A potential limitation of the APS is that it does not include rotational movements and has not yet been evaluated with regard to gait speed. The aims of this study were (i) to investigate the effect on APS of adding two components of arm rotation (APS6) and (ii) to determine the influence of gait speed on the APS measures, when applied to non-disabled adults. Forty-two subjects walked 10 m at a self-selected speed (1.34 m/s), and in addition a subgroup of 28 subjects walked at a slow speed (0.66 m/s) set by a metronome. Data were collected from markers in a whole-body set up and by eight optoelectronic cameras. The results demonstrated significantly higher APS6 than APS4 values for both arms, irrespective of gait speed. Speed condition, whether self-selected or slow, had a significant effect on both APS measures. The two additional arm components are suggested to provide relevant information about arm swing during walking. However, APS6 needs to be implemented in gait analysis of individuals with gait arm pathologies in order to further examine its utility. We recommend that gait speed should to be taken into account when using APS measures to quantify arm swing during gait.

Assessment of arm movements during gait in stroke - the Arm Posture Score.

The purpose of the study was to apply the Arm Posture Score (APS) to a stroke population, since comprehensive measures to quantify arm swing in the affected and non-affected arms during gait are lacking. A further aim was to investigate how gait speed and upper limb function estimated by clinical measures are related to the APS in the stroke group. The APS is the summarized root mean square deviation (RMSD) from normal, based on kinematics. Four arm movements (sagittal and frontal planes) as well as six arm movements (incorporating transversal plane) were included in the calculation of APS, referred to as APS4 and APS6, respectively. The study population consisted of 25 persons with stroke and 25 age- and gender-matched controls. The APS measures were significantly different between the affected and non-affected arms, as well as between the affected arm and the non-dominant arm of the controls (p≤0.001). Spasticity significantly influenced both APS measures, while speed only had a significant effect on the APS4. The APS measures correlated significantly to clinical measures of upper limb function. Both APS measures seem to be useful indices to quantify and discriminate between impaired and normal arm swing during gait after stroke. The variability of rotational arm movements needs to be studied further before considering the additional value of the APS6 over the APS4. When interpreting the APS, complementary kinematics should be taken into account, as the single value of the APS gives no information about the direction of the deviation.

Impact of stroke on anterior-posterior force generation prior to seat-off during sit-to-walk.

Force generation during sit-to-walk (STW) post-stroke is a poorly studied area, although STW is a common daily transfer giving rise to a risk of falling in persons with disability. The purpose of this study was to describe and compare strategies for anterior-posterior (AP) force generation prior to seat-off during the STW transfer in both subjects with stroke and in matched controls. During STW at self-selected speed, AP force data were collected by 4 force plates, beneath the buttocks and feet from eight subjects with stroke (>6 months after onset) and 8 matched controls. Subjects with post-stroke hemiparesis and matched controls generated a similar magnitude of total AP force impulses (F(1,71)=0.67; p=0.42) beneath buttocks and feet prior to seat-off during STW. However, there were significant group differences in AP force impulse generation beneath the stance buttock (i.e. the non-paretic buttock in the stroke group), with longer duration (F(1,71)=8.78; p<0.005), larger net AP impulse (F(1,71)=6.76; p<0.05) and larger braking impulse (F(1,71)=7.24; p<0.05) in the stroke group. The total braking impulse beneath buttocks and feet was about 4.5 times larger in the stroke group than in the control group (F(1,71)=8.84; p<0.005). An intra- and inter-limb dys-coordination with substantial use of braking impulses was demonstrated in the stroke group. This motor strategy differed markedly from the smooth force interaction in the control group. These results might be important in the development of treatment models related to locomotion post-stroke.