S. John Sullivan

Motor fitness in children and adolescents with traumatic brain injury.

OBJECTIVEnThis study examined the test-retest reliability of selected motor fitness test items among children with severe traumatic brain injury.nnnDESIGNnA cohort study consisting of two testing session, one week apart.nnnSETTINGnAll subjects were recruited from among the former clients of a pediatric rehabilitation center.nnnSUBJECTSnA convenience sample of 19 subjects, 13 boys and 6 girls aged 8 to 17 years, volunteered to participate. All participants had a diagnosis of a severe traumatic brain injury (X +/- SD = 5.88 +/- 1.71 on the Glascow Coma Scale), had completed a program of physical rehabilitation, and were evaluated at 4.16 +/- 2.61 years after their injury.nnnMAIN OUTCOME MEASURESnPerformance on twelve motor fitness test items (including flexibility, agility, muscular strength, cardiorespiratory endurance, power, muscular endurance, and coordination) was measured at each of two structured evaluation sessions.nnnRESULTSnNo differences (t tests, p < or = .05) were found between the performances on the two testing sessions for any of the variables. The test-retest reliability was established via the intraclass correlation (ICC) and ranged from .84 to .98, indicating almost perfect agreement.nnnCONCLUSIONnThe data indicate that these motor fitness testing protocols are reliable and applicable to traumatic brain injured children in a clinical setting and can thus be used by therapists to plan future interventions to improve the fitness of this clientele.

Motor profile of patients in minimally responsive and persistent vegetative states

The purpose of this descriptive clinical study is to document the motor characteristics of patients in minimally responsive and persistent vegetative states. Twelve subjects, presenting a prolonged altered state of consciousness (x = 7.82 years, range 2-27), aged 27-78 years (x = 50, SD = 15.26) were evaluated, using standardized protocols, on the following variables: passive range of motion, observed movements, reflexes, tonus, postural status and reactions. The subjects level of awareness and responsivity were measured with the Coma/Near Coma (CNC) scale at each of the three data collection sessions. While group CNC scores were stable over the three sessions, fluctuations in the level of awareness of individual subjects was recorded, confirming the heterogeneity of this clientele. Abnormal primitive reflexes were present in all subjects, with the flexor withdrawal (75%), the tonic labyrinthine (36%) and the body-on-body righting reaction (25%) being the most frequently observed. All subjects presented altered tonus, considerable posturing and varied degrees of reduced range of joint motion. A range of abnormal (e.g. chewing, clonus) and normal patterned (e.g. bridging, scratching) movement behaviours was recorded, but these did not translate into functional use, such as rolling. Collectively, the findings stress the complexity of the motor profile of patients in minimally responsive and vegetative states, and suggest the need for physiotherapists to become more actively involved in the evaluation and treatment of this clientele.

Prediction of motor status 3 and 6 months post severe traumatic brain injury: A preliminary study

The prediction of outcome following severe traumatic brain injury has received considerable attention in recent years. Previous prediction studies have focused on a long-term follow-up or prediction period. The reported outcome measures generally adopted a global approach (e.g. independent living) in terms of the prediction of physical function. The objective of the present study was to construct clinically useful predictive equations of motor system status, as represented by selected postural reactions (indicators of central nervous system function). Specifically, these equations would serve to predict the recovery of equilibrium and protective reactions both at 3 and 6 months post-injury, respectively. A stepwise multiple logistic regression analysis was performed, where nine predictive variables were considered using a multivariate approach. The results indicate that coma duration followed by age contribute significantly to the predictive capability of the models at both 3 and 6 months post-injury. Specifically, at 3 months, the predictive variables coma duration and age enabled an 84.62% correct prediction rate, whereas, at 6 months, coma duration and age enabled a 79.49% correct prediction rate. In addition, the exact probabilities (for given sample ages and coma durations) and associated 95% confidence intervals were calculated based on the predictive models obtained. The theoretical framework underlying these predictive models can form the basis for further studies. Furthermore, these preliminary predictive models have potential implications for early treatment planning and patient management.

Reliability of early motor function testing in persons following severe traumatic brain injury

The purpose of this study was to determine the intra- and inter-rater reliability of selected variables measuring motor function in adults following severe traumatic brain injury (TBI). Twelve adults with a severe TBI participated in the study and were assessed (independently) by two physical therapists with extensive clinical experience. Standardized testing protocols and two- or three-point ordinal rating scales were used to evaluate the following categories of variables: primitive reflexes, equilibrium/protective reactions and several motor skills. Intra-rater reliability was generally high for all variables, with kappa values exceeding 0.65 except for the scoring of equilibrium reactions in sitting and standing. Overall, inter-rater reliability was slightly lower, with kappa values ranging from 0.39 to 1.0, indicating fair to almost perfect agreement. The highest level of agreement was consistently reported for the scoring of motor skills. These results suggest that physical therapists trained in the use of standardized testing and scoring procedures can reliably assess primitive reflexes, equilibrium and protective reactions and a range of motor skills in TBI adults during the acute stage of recovery. Moreover, the results provide important information which will assist in the interpretation of data collected as part of a concurrently conducted longitudinal study of early motor recovery.

Changes in short and long latency stretch reflexes prior to movement initiation

The amplitudes of both short (M1) and long (M2) latency stretch reflexes mechanically elicited in the triceps brachii muscle were investigated prior to its voluntary activitation. The results obtained from 14 healthy subjects indicated that the amplitude of the M2 response increased steadily as the perturbation was delivered closer to the movement suggesting that the M2 changes are associated with the preparation to respond to the visual stimulus. In contrast, the amplitude of the M1 response showed no systematic variations over the same time period. This dissociation of the M1 and M2 reflex responses prior to movement may be attributable to selective gain modulation in supraspinal stretch reflex pathways or to descending projections to polysynaptic spinal pathways.

Reduction of H-reflex amplitude during the application of effleurage to the triceps surae in neurologically healthy subjects

The effects of effleurage, applied at a standardised rate (12 strokes/min) and pressure (2.5 kPa) to a 20–25 cm portion of the left triceps surae, were investigated. Sixteen healthy adults (8 men, 8 women) served as subjects. The experimental procedure consisted of four control (C1, C2, C3, C4) conditions with the massage condition interspersed between C2 and C3. Each condition lasted 3 min. During each of the five conditions, the posterior tibia1 nerve was stimulated with a rectangular electrical pulse of 1 msec duration every 10 sec. H-reflexes and concomitant m-responses were recorded from the ipsilateral triceps surae muscle. The mean peak-to-peak amplitudes of the H-reflex and m-responses were calculated for each condition and subjected to a one-way repeated measures ANOVA. A significant reduction [F(4,60) = 32.34, P<0.0001] in H-reflex amplitude was found between the massage (4.30 mV) and the four control conditions (5.73, 5.706, 5.99, 6.01 mV). No changes were observed in the m-responses, indicatin...

Movement refractoriness: The influence of response structure and speed ☆

Abstract In the first experiment, refractoriness of a primary arm swing was studied using two movement speeds and three secondary responses (reversal, contralateral and ipsilateral thumb-lift). Pre-movement inter-stimulus intervals were 100, 200 or 300 msec and response-stimulus intervals ranged from zero to 200 msec. Accelerometers provided kinematic data. The second experiment repeated the reversal condition with the addition of EMG analysis. The prediction that the maximal speed condition would show a general intensification of control processes, and thus less refractoriness as compared to submaximal speed, was upheld for all response conditions. The findings also supported the prediction that the pattern of refractoriness depends on the functional relationships of the muscles concerned. The EMG analysis revealed that while the sequencing of muscle action was unchanged with movement speed, its phasing characterized the shifts in response metrics. The overall findings emphasize the need to view the refractoriness phenomenon in the context of anatomical and mechanical consequences of force changes in controlling limb movement as they interact with intentional command.

The Recovery of Volitional Hand Movements Following a Severe Traumatic Brain Injury

The recovery of voluntary motor control of the hand following a severe traumatic brain injury was assessed in 31 patients (22 males and 9 females) at three time intervals: within 1 month of the injury, and at 3 and 6 months post-injury. Each patients performance (could, could not complete) on four motor tasks was assessed: grasp with a stimulus (GWS), grasp without a stimulus (GWOS), release without a stimulus (RWOS) and release with a stimulus (RWS) for both the left and right hands. Significant differences (McNemar chi-square, P<0.01) in performance were found between the initial (< 1 month) and both the 3- and 6-month assessments for all four variables for both hands (χ2, 9-15). Thus a meaningful number (n = 26) of the patients were observed to have recovered this voluntary function by 3 months post-injury. These data also suggest that these simple motor tasks may be used to monitor the recovery of voluntary hand control in the severe traumatically brain-injured patient in the early (acute care) phase...

Frequency characteristics of signals and instrumentation: Implication for EMG biofeedback studies

Signals can be analyzed in either the time or frequency domain. In the time domain, the analysis consists of manipulating and measuring one or more characteristics of the signal that may vary with time. One can, for instance, rectify a signal, filter it, calculate its mean value, display the histogram of its amplitude, and so forth. Frequency analysis is less well understood because it requires a lengthy mathematical treatment most easily done by computer. However, it gives exclusive information on a signal. For instance, when the frequency content of a signal is known, it is easy to specify which characteristics an amplifier must have in order to amplify the signal without distortion, or to set the cutoff frequencies of filters to eliminate noise. Also, in many circumstances, frequency spectra are more easily interpreted than the original raw data. Such is the case with the EMG where the random aspect of the signal makes some form of processing (i.e., rectification, filtering, etc.) necessary, but not always as meaningful as we would like. Thus we present here the principal characteristics of frequency analysis, and discuss its usefulness in analyzing EMG signals and its application to biofeedback, clinical practice, and research.