Improvement in gross motor performance between 3 and 5 years of age.

This study examined gross motor performance of 101 typically developing children between 3 and 5 years of age (48 boys, 53 girls, M age = 3.9 yr., SD = 0.5). All children performed 7 different gross motor tasks which were rated on a 5-point scale. Age and sex were assessed by an ordinal-logistic model, and odds ratios were calculated for each task using age and sex as covariates. For standing on one leg, walking on a beam, hopping on one leg, running, and taking stairs, statistically significant age differences were found, while for rising and jumping down, none were apparent. Mean motor performance did not differ between boys and girls on the tasks. The older the children were, the better they performed on the tasks.

Energetics of paraplegic cycling: adaptations to 12 months of high volume training.

PURPOSE: The efficiency of functional electrical-stimulation (FES) cycling in spinal cord injured and anaesthetised able-bodied cyclists has been found to be about one third of that reported during volitional cycling. The stimulation paradigm itself appears to be the main source of this inefficiency. It is unknown whether a period of high-volume training can induce adaptations that may influence the metabolic and electrical cost of FES cycling. METHOD: 11 individuals with paraplegia completed a 12-month, home-based, progressive FES cycle training programme (up to 5 × 60 min per wk). Stimulation cost, oxygen cost, efficiency and markers of anaerobic metabolism were determined before and after 6 and 12 months of training, during constant work-rate tests. RESULTS: Oxygen cost and efficiency did not significantly change after training. Total stimulation cost and blood lactate values reduced overall, while respiratory exchange ratios remained relatively high. CONCLUSIONS: The high metabolic cost of FES cycling is a result of non-physiological recruitment of predominantly fast muscle fibres. The electrical cost of cycling reduced by 37%, probably due to motor unit hypertrophy, and lactate oxidation capacity improved.

Determination and possible application of the aerobic gas exchange threshold in aerobically untrained paraplegic subjects based on stimulated cycle ergometry.

PURPOSE: To accurately characterise cardiopulmonary baseline performance in aerobically untrained paraplegic subjects by means of an incremental exercise test (IET) and to derive possible training recommendations based on these measurements. METHODS: Twelve motor complete paraplegic subjects with no previous experience in stimulated leg-cycling participated in the study. Exercise testing was performed on a recumbent FES-tricycle by means of a work rate and cadence controlled IET until maximal work rate was reached. Heart rate (HR) and respiratory parameters were recorded continuously. RESULTS: Peak oxygen uptake was 671 +/- 192 mL min(-1) (mean + standard deviation), peak HR 90 +/- 12 beats min(-1), net peak power 8.4 +/- 3.3 W and peak minute ventilation 23.6 +/- 7.5 L min(-1). Aerobic gas exchange threshold (GET) was found to be 51% +/- 10% of peak oxygen uptake and corresponded to 41% +/- 13% of peak power. CONCLUSIONS: A cadence and work rate controlled exercise test allows the determination of cardiopulmonary parameters during stimulated cycle ergometry even in aerobically untrained paraplegic subjects. The precise determination of GET allows an appropriate exercise intensity to be prescribed and thus provides a suitable method for exercise intensity calculation in the spinal cord injured population in the future.

Energetics of paraplegic cycling: a new theoretical framework and efficiency characterisation for untrained subjects.

Complete lower-limb paralysis resulting from spinal cord injury precludes volitional leg exercise, leading to muscle atrophy and physiological de-conditioning. Cycling can be achieved using phased stimulation of the leg muscles. With training there are positive physiological adaptations and health improvement. Prior to training, however, power output may not be sufficient to overcome losses involved in rotating the legs and little is known about the energetics of untrained paralysed muscles. Here we propose efficiency measures appropriate to subjects with severe physical impairment performing cycle ergometry. These account for useful internal work (i.e. muscular work done in moving leg mass) and are applicable even for very low work rates. Experimentally, we estimated total work efficiency of ten untrained subjects with paraplegia to be 7.6 +/- 2.1% (mean +/- SD). This is close to values previously reported for anaesthetised able-bodied individuals performing stimulated cycling exercise, but is less than 1/3 of that of able-bodied subjects cycling volitionally. Correspondingly, oxygen cost of the work (38.8 +/- 13.9 ml min(-1) W(-1)) was found to be approximately 3.5 times higher. This indicates the need, for increased power output from paralysed subjects, to maximise muscle strength through training, and to improve efficiency by determining better methods of stimulating the individual muscles involved in the exercise.

Coordination training in individuals with incomplete spinal cord injury: consideration of motor hierarchical structures.

STUDY DESIGN: Clinical commentary. OBJECTIVE: To discuss the method of coordination training to enhance motor skills in persons after spinal cord injury (SCI). METHOD: From the literature and clinical experience, we learn that basic motor skills like walking are refined and maintained through the millions of repetitions that take place as part of normal development. These coordinated patterns function effectively as a form of training to the system because of the presence of neural pathways that mediate commands between higher and lower levels of the central nervous system (CNS). When these pathways are disrupted as a result of a lesion, the question that arises is whether retraining can be effective. RESULTS/DISCUSSION: The question is directed at the common practice among rehabilitation professionals to prescribe and carry out tireless repetitions of coordinated motor activities in people with SCI lesions. We discuss this fundamental question from the perspective of understanding differences in maturation and function of higher motor centres and lower motor centres.

The effect of passive cycling movements on spasticity after spinal cord injury: preliminary results.

OBJECTIVE: To investigate the influence of rhythmic passive movements of the legs on the reduction of spasticity after spinal cord injury (SCI). SETTING: Swiss Paraplegic Centre Nottwil, Switzerland. METHODS: A total of 10 subjects with motor complete SCI were treated with a cycling device for half an hour. Before and after cycling their spasticity was tested with an isokinetic dynamometer. The subjects were tested one week later by exactly the same procedure with a half an hour break instead of the cycling. Subjects were asked about their spasticity before and after the cycling and break. RESULTS: There was no significant difference in elicited peak torque either before and after the cycling, or before and after the break (MANOVA, P<0.05). Six out of 10 subjects estimated their spasticity as less after the cycling. CONCLUSION: With the isokinetic dynamometer, it was not possible to show an effect of passive cycling on spasticity reduction. However, six out of 10 of the subjects estimated their spasticity to be less after cycling. This positive effect might be attributed to a reduced spasticity in the trunk and/or to the attention the subjects perceived during the intervention.

Effects of different sodium concentrations in replacement fluids during prolonged exercise in women.

OBJECTIVE: To investigate the effect of different sodium concentrations in replacement fluids on haematological variables and endurance performance during prolonged exercise. METHODS: Thirteen female endurance athletes completed three four hour runs on a 400 m track. Environmental conditions differed between the three trials: 5.3 degrees C and snow (trial 1), 19.0 degrees C and sunny weather (trial 2), 13.9 degrees C and precipitation (trial 3). They consumed 1 litre of fluid an hour during the trials with randomised intake of fluids: one trial (H) with high sodium concentration (680 mg/l), one trial (L) with low sodium concentration (410 mg/l), and one trial with only water (W). Before and after the trials, subjects were weighed and blood samples were taken for analysis of [Na(+)](plasma), packed cell volume, and mean corpuscular volume. RESULTS: The mean (SD) decrease in [Na(+)](plasma) over the whole trial was significantly (p<0.001) less in trial H (2.5 (2.5) mmol/l) than in trial W (6.2 (2.1) mmol/l). Mild hyponatraemia ([Na(+)](plasma) = 130-135 mmol/l) was observed in only six women (46%) in trial H compared with nine (69%) in trial L, and 12 (92%) in trial W. Two subjects (17%) in trial W developed severe hyponatraemia ([Na(+)](plasma)<130 mmol/l). No significant differences were found in performance or haematological variables with the three different fluids. There was no significant correlation between[Na(+)](plasma) after the run and performance. There was a significant correlation between changes in [Na(+)](plasma) and changes in body weight. CONCLUSIONS: Exercise induced hyponatraemia in women is likely to develop from fluid overload during prolonged exercise. This can be minimised by the use of replacement fluids of high sodium concentration. Sodium replacement of at least 680 mg/h is recommended for women in a state of fluid overload during endurance exercise of four hours. However, higher [Na(+)](plasma) after the run and smaller decreases in [Na(+)](plasma) during the trials were no indication of better performance over four hours.

Characteristics of sleep apnea syndrome in tetraplegic patients.

OBJECTIVE: To include a larger number of tetraplegics than in previous studies, in order to more reliably characterize the pathogenesis and predisposing factors of sleep apnea in tetraplegia. METHODS: Sleep breathing data and oxymetric values were investigated in 50 randomly selected tetraplegic patients and discussed in context with age, gender, BMI, neck circumference, type and height of lesion, time after injury, spirometric values and medication. A non-validated short questionnaire on daytime complaints was added. RESULTS: Thirty-one patients out of 50 had an RDI > or =15, defined as sleep disordered breathing (SDB); 24 of them combined with an apnea index of 5 or more, these cases were diagnosed as sleep apnea syndrome (SAS). SAS was apparent in 55% and 20% of the studied men and women, respectively. Regression analyses showed no significant correlation between RDI and lesion level, ASIA impairment scale or spirometric values. In contrast, a significant correlation between RDI and age, BMI, neck circumference and time after injury could be shown. Kruskal-Wallis test for dichotomous non-parametric factors, such as gender, cardiac medication and daytime complaints, showed significant differences with regard to RDI. In contrast to able-bodied people with SAS, daytime complaints were only present in tetraplegic patients with severe pathology (RDI>40). CONCLUSION: Incidence of SAS is high in tetraplegia, particularly in older male patients with large neck circumference, long standing spinal cord injury and under cardiac medication. As tetraplegics with RDI between 15 and 40 reported no daytime complaints and often have normal BMI, these tetraplegics are not clinically suspicious for SAS. The increased use of cardiac medication in tetraplegics with SAS may implicate a link between SAS and cardiovascular morbidity, one of the leading causes of death in tetraplegia.

The importance of posture on the isokinetic assessment of spasticity.

OBJECTIVE: To measure spasticity of the knee flexors and extensor muscles in two different hip positions. SETTING: Swiss Paraplegic Center Nottwil, Switzerland. METHODS: Twenty spinal cord injured (SCI) patients with complete lesions were tested with a torque-velocity dynamometer in the following positions: (1) supine with a hip angle of 0 degrees; (2) sitting with a hip angle of 90 degrees. The excursion of the knee was measured for both positions using a goniometer. Two flexion/extension movements of the knee were performed at a speed of 10 degrees per sec. A further four flexion/extension movements over the same trajectory were made at a speed of 120 degrees per sec. Eccentric peak torques were measured continuously during movement of both legs for both speeds. RESULTS: At a speed of 120 degrees per second, there was a significant difference in stretch reflex of the hamstrings and quadriceps femoris muscles for the two positions (Wilcoxon's paired t-test, P<0.05). Excitability was higher for the quadriceps femoris muscles in supine than in sitting position. For the hamstrings, the effect was reversed. Significant differences between sitting and supine position were not found for the speed of 10 degrees per sec. Test-retest reliability was high for the movements of 120 degrees per sec but low for 10 degrees per sec. CONCLUSIONS: Our findings indicate that for a reliable and comparable measurement of spasticity, an exact description of test position and procedure is essential.

Movement quality in preterm infants prior to term.

Quality of spontaneous movement behavior (fluency, spatio-temporal variation and sequencing) was studied from birth to term in high-risk preterm (n = 18), low-risk preterm (n = 18) and term (n = 20) infants. Cranial ultrasonography was performed during the first week of life and the child's general health was considered. The results were as follows: (1) In their first week of life, preterm infants displayed lower scores on all quality parameters when compared to term infants (p < 0.001). (2) Quality of spatiotemporal variation and sequencing decreased up to term (p < 0.01). These findings could be attributed to maturational differences, too early exposure to an extrauterine environment, and cerebral lesions.

Differences in movement quality at term among preterm and term infants.

Significant differences in movement quality at term are reported in high-risk preterm (n = 18), low-risk preterm (n = 21) and term (n = 20) infants. Movement quality was judged using 2-minute video collection of general movements; three parameters of movement quality could be assessed reliably in a semiquantitative way: fluency, spatiotemporal variability and sequencing. The parameters fluency and variability correlated highly with each other (r = 0.47-0.99) while their correlations with sequencing were less (r = 0.42-0.67). Significant differences on all quality parameters were noted between term, low-risk preterm and high-risk preterm infants (p < 0.001-0.05). The findings indicate a significant impact of prematurity per se and brain damage on movement quality.

Some aspects of the reliability of Touwen's examination of the child with minor neurological dysfunction.

Three studies concerning the inter-rater and test-retest reliability of the Touwen examination are presented. The results of the first study showed that it was not possible to achieve acceptable levels of reliability using the manual as the only reference for instruction. Although the reliability estimates of the total scores were good, inter-rater reliability for the nine groups of items and the individual tasks within them was poor. When methodology and interpretation of performance was agreed between observers, a second study showed that these disagreements diminished. The third study demonstrated that the short-term stability of total scores is good, but reliability for group and individual item scores remained poor.