Effect of arm cranking exercise on skin blood flow of lower limb in people with injuries to the spinal cord

The purpose of this study was to examine whether arm cranking exercise induces changes in skin blood flow in the paralyzed lower limbs of people with injuries to the spinal cord (PISC). Ten PISC with lesions located between Th5 and L5 and six control subjects performed arm cranking exercise for 6 min at three intensities, 10, 30 and 50 W, at a room temperature of 25°C. Oxygen uptake (Vo₂) and heart rate (HR) were measured for the last 2 min of each exercise period. The skin blood flow at the anterior thigh (BF_sk,t) was continuously monitored using laser Doppler flowmetry for the whole 6-min period and for the first 10 min of recovery following exercise. During exercise, the PISC showed lower Vo₂ and greater HR than the control subjects. No increase in BF_sk,t was found in six of the PISC with lesions at or above Th12, irrespective of the exercise intensity. On the other hand, in PISC with lesions at L1 or below, BF_sk,t increased significantly (P < 0.05) with an increase in Vo₂ and HR, although the BF_sk,t at a given Vo₂ and HR was lower than that in the control subjects. These results would suggest that arm exercise can promote the blood circulation in the skin of the lower limbs if the injury level is below L1.     

Time-related effects of general functional training in spinal cord-injured rats

OBJECTIVES:

This prospective, randomized, experimental study with rats aimed to investigate the influence of general treatment strategies on the motor recovery of Wistar rats with moderate contusive spinal cord injury.

METHODS:

A total of 51 Wistar rats were randomized into five groups: control, maze, ramp, runway, and sham (laminectomy only). The rats underwent spinal cord injury at the T9-T10 levels using the NYU-Impactor. Each group was trained for 12 minutes twice a week for two weeks before and five weeks after the spinal cord injury, except for the control group. Functional motor recovery was assessed with the Basso, Beattie, and Bresnahan Scale on the first postoperative day and then once a week for five weeks. The animals were euthanized, and the spinal cords were collected for histological analysis.

RESULTS:

Ramp and maze groups showed an earlier and greater functional improvement effect than the control and runway groups. However, over time, unexpectedly, all of the groups showed similar effects as the control group, with spontaneous recovery. There were no histological differences in the injured area between the trained and control groups.

CONCLUSION:

Short-term benefits can be associated with a specific training regime; however, the same training was ineffective at maintaining superior long-term recovery. These results might support new considerations before hospital discharge of patients with spinal cord injuries.     

Cardiac effects of short term arm crank training in paraplegics: echocardiographic evidence

Summary The cardiac responses of male paraplegics to upper-body endurance training have been studied by M-mode echocardiography and CO₂-rebreathing determination of cardiac output. Data for nine exercised subjects are compared with 5 controls. After 16 weeks of arm ergometer exercise, heart rates of trained individuals were 9 bt · min^–1 lower during isometric handgrip effort (30% of MVC for 3 min), with a substantial decrease of rate pressure product (20%;p<0.05). In contrast (possibly because of greater anticipation) the control subjects developed a larger rate-pressure product with repitition of the standard isometric effort. Despite a significant increase of peak (19% and 31% after 8 and 16 weeks, respectively;p<0.05), echocardiographic LV mass, dimensions and indices of LV performance were unchanged by training, either at rest or during the isometric handgrip. Stroke volumes were significantly increased by 12–16% after training, both in isometric and in rhythmic work; at the highest intensity of arm ergometry, there was also a suggestion of increased cardiac output. We conclude that (1) a short period of arm training is insufficient to induce cardiac hypertrophy, (2) an increase of stroke volume with a decreased ratepressure product but no change in echocardioraphic indices of LV performance implies an improved myocardial efficiency. Possible explanations are (1) a greater strength of the trained arms, and (2) some increase of pre-loading (due to an increase of venous tone and more effective operation of the muscle pump after training).     

The effect of electrical stimulation on leg muscle pump activity in spinal cord-injured and able-bodied individuals

The purpose of this study was to examine the difference in: (1) effective muscle pump activity (MPA) between voluntary and electrically (ES) induced contractions in able-bodied subjects (ABS); and (2) ES-induced MPA between spinal cord-injured (SCI) individuals and ABS. MPA was measured as relative volume changes in the calf using strain-gauge plethysmography during repeated muscle contractions in the supine position while venous outflow was impeded by a thigh cuff inflated to a range of pressures. Ten SCI individuals and ten ABS participated in this study. ABS showed no significant difference between voluntary and electrically induced MPA [58.1 (18.4)% versus 67.7 (8.7)%, respectively]. SCI individuals showed a significantly lower ES-induced MPA than ABS [21.5 (15.9)% versus 67.7 (8.7)%, respectively]. The low MPA in SCI individuals may be explained by: (1) extensive leg muscle atrophy and/or (2) an “atrophic” vascular system in the legs. The electrical current level seemed to influence MPA (43 mA, 21.5% versus 60 mA, 30.8%) for SCI individuals, whereas no influence of muscle contraction rate on MPA was observed in ABS. The results of this study demonstrate that although ES-induced leg muscle contractions result in adequate MPA in ABS, it leads to significantly less effective MPA in SCI individuals. Accepted: 21 March 2000     

The relationship between exercise work intervals and duration of exercise on lower extremity training induced by electrical stimulation in humans with spinal cord injuries

A group of 90 male paraplegics were studied to determine the optimal training protocol for isokinetic exercise induced by functional electrical stimulation of the quadriceps muscles. The parameters that were varied were the number of training sessions a week, the length of the training sessions each day, and the work-rest intervals in each training session. Training for 3 days a week for 30 min a day with 6 s of exercise and 6 s of rest proved the optimal protocol. Training for 5 days or for 1 day a week was not as effective in training strength or endurance. A combination of 50% work and 50% rest produced a much greater gain in strength and endurance than work:rest ratios of 66%:33% or 25%:75%. When training was conducted for 5 min, 15 min or 30 min each day, the greatest increase was found when the muscles were exercised for 30 min each day. While more variables need to be examined, this study has provided some initial guidelines for isokinetic training of humans using electrical stimulation. Accepted: 9 April 2000     

Information seeking behavior and perceived health literacy of family caregivers of persons living with a chronic condition. The case of spinal cord injury in Switzerland

ObjectiveTo examine the information seeking behavior and health literacy of caregivers of individuals living with spinal cord injury in Switzerland and their impact on the caregiving experience.MethodsNationwide survey of family caregivers of people with spinal cord injury (N = 717). Caregivers aged 18+ who assisted with activities of daily living were included. Self-reported information seeking behavior, including topics, preferred sources, and health literacy were assessed and analyzed.ResultsHealth professionals were the most trusted source of information. Among information-seekers, higher health literacy levels were shown to be associated with lower subjective caregiver burden and, in turn, with higher caregivers’ satisfaction with own health.ConclusionCaregivers use information on different topics and coming from different sources. In order for information to improve the caregiving experience, however, caregivers need health literacy skills to make sense of it.Practice implicationsBuilding health literacy is a promising approach to support caregivers in their activities, reduce their subjective burden, and even to improve their health. Interventions should consider involving health professionals, as the most trusted source of information, and address both health-related and more practical issues.     

No association of sleep with total daily physical activity in normal sleepers

The aim of two studies was to examine both between-subjects and within-subjects associations between daily amounts of physical activity and sleep in the home environment. Study 1 examined self-reported exercise durations and sleep diaries for 105 consecutive days in 31 college students who were normal sleepers. Between-subjects associations of mean exercise with mean sleep were assessed with Spearman rank-order correlations. Within-subjects correlations were determined across 105 days, and by comparing sleep on the 11 most active vs. the 11 least active days. Study 2 examined 71 physically active adults (n=38 ages 18-30 years, and n=33 ages 60-75 years), the majority of whom were normal sleepers. Over seven consecutive days, physical activity was assessed via actigraphy and a diary-derived estimate of energy expenditure, and sleep was assessed via actigraphy and sleep diaries. Between-subjects associations of mean physical activity with mean sleep were assessed with partial correlations, controlling for age. Within-subjects associations were assessed with ANCOVAs, with daily physical activity serving as the covariate, and by comparing sleep on the most active vs. the least active day. No significant within-subjects associations between physical activity and sleep were found in the main analyses of either study. Two small, but significant, between-subjects correlations between different physical activity measures and subjective sleep were found in Study 2. These results fail to support epidemiologic data on the value of exercise for sleep, but are consistent with experimental evidence showing only modest effects of exercise on sleep.     

Day-to-day variability in voluntary wheel running among genetically differentiated lines of mice that vary in activity level

This study examined the day-to-day variability in voluntary wheel-running behavior among three genetically distinct lines of young male and female mice. Daily wheel revolutions were recorded at an age of 6–8 weeks in 10 males and 10 females from each of 3 lines: selectively bred line for high wheel running (Line 8), selectively bred for high wheel-running activity and fixed for a Mendelian recessive allele that reduces hind-limb muscle mass by 50% (Line 3), non-selected control (Line 2). There were significant mean differences in revolutions/day among weeks (P = 0.003), but the effect size was small (10%). Significant main effects for wheel running were also revealed for sex and line (P < 0.001). The grand mean ± SD for the coefficient of variation (CV) of intra-individual wheel running was 23.0 ± 10.8%. Although a significant main effect for the CV was found for week, the effect size was low (7%) (age 6 weeks, 23.4 ± 10.9%; age 7 weeks, 25.1 ± 13.2%; age 8 weeks, 20.1 ± 7.8%). The overall mean CV was similar between females (21.4 ± 9.8%) and males (24.4 ± 12.0%) and among lines (Line 2, 23.4 ± 9.8%; Line 3, 20.4 ± 7.6%; and Line 8, 25.0 ± 14.4%). These findings are consistent with our previous work in young humans and lend further support for the hypothesis that biological mechanisms influence daily levels of physical activity.     

Effect of acute unloaded arm versus leg cycling exercise on the soleus H-reflex in adults with multiple sclerosis

This study compared the effect of acute bouts of unloaded arm versus leg cycling exercise on spasticity of the lower legs in persons with multiple sclerosis (MS) and then examined post-activation depression (PAD) as a possible mechanism for the anti-spastic effects of acute exercise. Participants (N = 10) had relapsing-remitting MS, slight to moderate spasticity of the soleus muscle, and were independently ambulatory. Spasticity was measured in the soleus muscle using the H-reflex and modified Ashworth scale (MAS). PAD was measured in the soleus muscle based on a simple, standardized protocol for modifying the parameters for evoking the H-reflex. In three separate sessions participants undertook 20 min of either unloaded arm cycling exercise, unloaded leg cycling exercise, or control (quiet sitting) conditions in a random order, and data were collected before and after all three conditions. The H-reflex and MAS were significantly decreased after both unloaded arm and leg cycling exercise and significantly increased after quiet sitting. There was no change over time in PAD among the conditions. The reduction in the H-reflex was ∼50% larger after leg than arm cycling exercise, whereas the reduction in MAS scores was ∼20% larger after leg than arm cycling exercise. Such findings provide support for anti-spastic potential of both arm and leg cycling exercise on spasticity of the legs, but indicate that the effect is larger for the musculature that is activated during cycling and not explained by PAD.     

Determination of the maximal fat oxidation point in obese children and adolescents: validity of methods to assess maximal aerobic power

We aimed to examine the interchangeability of techniques used to assess maximal oxygen consumption () and maximal aerobic power (MAP) employed to express the maximal fat oxidation point in obese children and adolescents. Rate of fat oxidation were measured in 24 obese subjects (13.0 ± 2.4 years; Body Mass Index 30.2 ± 6.3 kg m⁻²) who performed a five 4-min stages submaximal incremental cycling exercise. A second cycling exercise was performed to measure . Results are those of the 20 children who achieved the criterion of RER (>1.02) to assess the attainment of . Although correlations between results obtained by different methods were strong, Bland–Altman plots showed little agreement between the maximal fat oxidation point expressed as a percentage of measured and as % estimated according to ACSM guidelines (underestimation : −5.9%) or using the predictive equations of Wasserman (−13.9%). Despite a mean underestimation of 1.4% several values were out of the limits of agreement when comparing measured MAP and Theoretical MAP. Estimations of lead to underestimations of the maximal fat oxidation point.     

Metabolism of energy-yielding substrates in patients with liver cirrhosis

Correspondence to: M.J. Müller at his present address     

Comparison of heart rate monitoring combined with indirect calorimetry and the doubly labelled water (2H2 18O) method for the measurement of energy expenditure in children

Summary The aim of the present study was to compare data on 24-h energy expenditure (EE_{24 h}) in nine boys and ten girls (mean age 9.3 and 8.1 years, respectively) by heart rates (f _c) combined with energy expenditure obtained from a 1-day stay in an indirect calorimeter (EE_cal) and a 2-week period of normal living using the doubly labelled water method (EE_dlw). Individual calibration curves were derived fromf _c and oxygen uptake measured during sleep (in the calorimeter), standing and walking on a treadmill. An estimation of energy expenditure based on 24-hf _c, monitoring (EEf _c) was made during the stay in the calorimeter and on a normal school-day. Mean results showed an overestimation in EE _fc compared to EEcal and EEdlw of 10.4% and 12.3% respectively, varying from 6.3% to 16.2%. These results confirmed earlier observations in adults that for a group thef _c method overestimates EE_{24 h} by about 10%.     

脊髓损伤患者E-MAG和落环锁式膝踝足矫形器的应用对比

背景：落环锁式膝踝足矫形器在较高位脊髓损伤患者中被广泛应用,但该矫形器在行走时有一个主要限制即摆动期膝关节锁定,导致患者在行走时需要通过上肢活动来补偿。目前有关不同矫形器治疗效果的对比鲜有研究。 目的：探究并对比E-MAG活跃型矫形器和落环锁式膝踝足矫形器在脊髓损伤患者步态提升中的临床效果。 方法：采用自身交叉对照研究的实验设计,观察E-MAG活跃型矫形器和落环锁式膝踝足矫形器在1例T10脊髓水平损伤患者中的应用效果。通过测量下肢的三维步态数据,对比摆动期允许膝关节屈曲、支撑期膝关节锁定和整个步态周期中膝关节均锁定两种步态的差异。 结果与结论：定性观察和运动学三维步态数据证明该患者在使用E-MAG活跃型矫形器时行走更快,更有效。尽管患者无法自主控制其膝关节,由于摆动期膝关节屈曲,支撑期膝关节锁定,使用E-MAG活跃型矫形器可以帮助患者在行走时更加安全和顺利,且需要的上肢补偿更加少。与落环锁膝式膝踝足矫形器相比,E-MAG活跃型矫形器包含站立期控制,因此会有更高的接受度和实用性