Effects of treadmill exercise on transcranial magnetic stimulation-induced excitability to quadriceps after stroke

OBJECTIVE: To determine characteristics of transcranial magnetic stimulation (TMS)-induced measures of central motor excitability to the paretic and nonparetic quadriceps muscles of chronic hemiparetic stroke patients in the context of a short-term, submaximal bout treadmill exercise. DESIGN: Cross-sectional. SETTING: Motor control and gait biomechanics laboratory. PARTICIPANTS: Convenience sample of 11 patients including cohorts of treadmill untrained (n=8) and trained (n=3) stroke patients with chronic hemiparetic gait. INTERVENTION: Short-term submaximal treadmill exercise. MAIN OUTCOME MEASURES: Thresholds, amplitudes and latencies of TMS-induced motor evoked potentials at vastus medialis in paretic and nonparetic lower extremities. RESULTS: Baseline characteristics of the motor evoked potentials (MEPs) show significantly higher motor thresholds, longer latencies, and reduced amplitudes on the paretic side. In cross-sectional comparisons a group of treadmill-trained patients had greater paretic MEP amplitude changes after treadmill exercise versus paretic MEP responses from a group of untrained patients. CONCLUSIONS: These results indicate that treadmill training for 3 months or more may alter responsiveness of the lower-extremity central motor pathways to a short-term treadmill stimulus.     

Task-oriented treadmill exercise training in chronic hemiparetic stroke

Patients with stroke have elevated hemiparetic gait costs secondary to low activity levels and are often severely deconditioned. Decrements in peak aerobic capacity affect functional ability and cardiovascular-metabolic health and may be partially mediated by molecular changes in hemiparetic skeletal muscle. Conventional rehabilitation is time delimited in the subacute stroke phase and does not provide adequate aerobic intensity to reverse the profound detriments to fitness and function that result from stroke. Hence, we have studied progressive full body weight-support treadmill (TM) training as an adjunct therapy in the chronic stroke phase. Task-oriented TM training has produced measurable changes in fitness, function, and indices of cardiovascular-metabolic health after stroke, but the precise mechanisms for these changes remain under investigation. Further, the optimal dose of this therapy has yet to be identified for individuals with stroke and may vary as a function of deficit severity and outcome goals. This article summarizes the functional and metabolic decline caused by inactivity after stroke and provides current evidence that supports the use of TM training during the chronic stroke phase, with protocols and inclusion/exclusion criteria described. Our research findings are discussed in relation to associated research.     

Effects of unilateral robotic limb loading on gait characteristics in subjects with chronic stroke

Background  

Hemiparesis after stroke often leads to impaired ankle motor control that impacts gait function. In recent studies, robotic devices have been developed to address this impairment. While capable of imparting forces to assist during training and gait, these devices add mass to the paretic leg which might encumber patients' gait pattern. The purpose of this study was to assess the effects of the added mass of one of these robots, the MIT's Anklebot, while unpowered, on gait of chronic stroke survivors during overground and treadmill walking.     

Asymmetric lower-limb bone loss after spinal cord injury: case report

Osteoporosis is a significant secondary condition that occurs acutely after spinal cord injury (SCI). This article reports on a patient with motor incomplete SCI and asymmetric lower-limb bone loss as it correlates with lower-limb motor function and gait characteristics. A 32-year-old Caucasian male completed a comprehensive inpatient rehabilitation program, including 3 months of robotic body-weight-supported treadmill training three times a week. Bone mineral density (BMD) was monitored up to 1.5 years post-SCI by dual-energy X-ray absorptiometry. Ground reaction forces were measured through an instrumented treadmill for bilateral weight-bearing comparison. At 1.5 years postinjury, neurological examination revealed thoracic 4 American Spinal Injury Association Impairment Scale D SCI with less strength, reduced weight bearing, and lower BMD in the more neurologically impaired leg. These results suggest that osteoporosis may vary according to severity of impairment within individuals and that monitoring lower-limb BMD is especially important for patients who ambulate.     

Effect of treadmill exercise training on spatial and temporal gait parameters in subjects with chronic stroke: a preliminary report

The effects of task-repetitive locomotor training on stroke patients' spatial and temporal gait parameters during unassisted walking are not well understood. This study determined the effects of treadmill aerobic exercise (T-EX) on spatial and temporal gait parameters that underlie changes in overground walking function. Thirty-nine subjects with hemiparetic stroke underwent T-EX three times weekly for 6 months. We measured the subjects pre- and posttraining on 30-foot timed walks and 6-minute distance walks with usual assistive devices and on an 8 m instrumented walkway without assistive devices. T-EX improved 30-foot walks by 17% and 6-minute walks by 23%. Unassisted walking velocity increased 22%, stride length increased 13%, and cadence increased 7%. Paretic and nonparetic step lengths increased significantly, and respective step times decreased significantly. Interlimb symmetry did not change. This study presents preliminary evidence that changes in spatial and temporal gait parameters contribute to the increased velocity of subjects with stroke after T-EX.     

Effects of loading the unaffected limb for one session of locomotor training on laboratory measures of gait in stroke

BACKGROUND: Walking following stroke involves compensatory strategies by the unaffected leg to cope with the deficits in the hemiparetic leg. Recently, training paradigms based on the principles of task-oriented repetitive exercise have provided a valuable insight regarding the influence of restraining compensatory movements to improve motor performances. We investigated changes in the walking movements of each lower extremity after weighting the unaffected leg. METHODS: Ten individuals early after a stroke (range: 3-7 months) who were able to walk 10 m with no aids, participated to this study. Subjects were instructed to walk on a treadmill with an external mass attached around the non affected ankle during a single session. The short-term effects on gait performance were quantified by a 3D-gait analysis system before, immediately after and 20 min after the walking technique. FINDINGS: A one factor repeated measures model revealed that stroke participants significantly improved in walking speed (P<0.001), step length (P<0.01) and cadence (P<0.01). Weight-bearing on the paretic leg increased (P<0.01) along with kinematic modifications including greater hip and knee excursion. When the mass was removed, these adaptations were maintained 20 min later. INTERPRETATION: Preliminary findings suggest that even brief gait training using a treadmill with a restrictive weight placed on the distal extremity of the non-hemiplegic lower limb can improve laboratory measures of gait ability in a sample of stroke subjects. Future studies must evaluate the effect of this technique in longer-term locomotor retraining.     

Effect of single-session dual-tDCS before physical therapy on lower-limb performance in sub-acute stroke patients: A randomized sham-controlled crossover study

Anodal stimulation increases cortical excitably, whereas cathodal stimulation decreases cortical excitability. Dual transcranial direct current stimulation (tDCS; anodal over the lesioned hemisphere, cathodal over the non-lesioned hemisphere) was found to enhance motor learning. The corresponding tDCS-induced changes were reported to reduce the inhibition exerted by the unaffected hemisphere on the affected hemisphere and restore the normal balance of the interhemispheric inhibition. Most studies were devoted to the possible modification of upper-limb motor function after tDCS; however, almost no study has demonstrated its effects on lower-limb function and gait, which are also commonly disordered in stroke patients with motor deficits. In this randomized sham-controlled crossover study, we included 19 patients with sub-acute stroke. Participants were randomly allocated to receive real or sham dual-tDCS followed by conventional physical therapy with an intervention interval of at least 1 week. Dual-tDCS was applied over the lower-limb M1 at 2-mA intensity for 20 min. Lower-limb performance was assessed by the Timed Up and Go (TUG) and Five-Times-Sit-To-Stand (FTSTS) tests and muscle strength was assessed by peak knee torque of extension. We found a significant increase in time to perform the FTSST for the real group, with improvements significantly greater than for the sham group; the TUG score was significantly increased but not higher than for the sham group. An after-effect on FTSTS was found at approximately 1 week after the real intervention. Muscle strength was unchanged in both limbs for both real and sham groups. Our results suggest that a single session of dual-tDCS before conventional physical therapy could improve sit-to-stand performance, which appeared to be improved over conventional physical therapy alone. However, strength performance was not increased after the combination treatment.     

High-intensity functional exercise program and protein-enriched energy supplement for older persons dependent in activities of daily living: a randomised controlled trial

The aims of this randomised controlled trial were to determine if a high-intensity functional exercise program improves balance, gait ability, and lower-limb strength in older persons dependent in activities of daily living and if an intake of protein-enriched energy supplement immediately after the exercises increases the effects of the training. One hundred and ninety-one older persons dependent in activities of daily living, living in residential care facilities, and with a Mini-Mental State Examination (MMSE) score of ? 10 participated. They were randomised to a high-intensity functional exercise program or a control activity, which included 29 sessions over 3 months, as well as to protein-enriched energy supplement or placebo. Berg Balance Scale, self-paced and maximum gait speed, and one-repetition maximum in lower-limb strength were followed-up at three and six months and analysed by 2 x 2 factorial ANCOVA, using the intention-to-treat principle. At three months, the exercise group had improved significantly in self-paced gait speed compared with the control group (mean difference 0.04 m/s, p = 0.02). At six months, there were significant improvements favouring the exercise group for Berg Balance Scale (1.9 points, p = 0.05), self-paced gait speed (0.05 m/s, p = 0.009), and lower-limb strength (10.8 kg, p = 0.03). No interaction effects were seen between the exercise and nutrition interventions. In conclusion, a high-intensity functional exercise program has positive long-term effects in balance, gait ability, and lower-limb strength for older persons dependent in activities of daily living. An intake of protein-enriched energy supplement immediately after the exercises does not appear to increase the effects of the training.     

Post-stroke exercise rehabilitation: what we know about retraining the motor system and how it may apply to retraining the heart

A plateau in recovery within the first few months of rehabilitative therapy was assumed to be the norm in stroke survivors. Recent studies in our laboratory examined the effect of 6 months of treadmill exercise training in chronically disabled stroke survivors. Treadmill exercise improves fitness and walking ability in patients when initiated 6 months or more following their index stroke. Functional imaging studies show that such exercise also induces subcortical reorganization in these patients. Future investigations will explore the relationship between these functional and structural effects and characterize the therapeutic mechanisms of post-stroke rehabilitation. Nonetheless, treadmill exercise appears to have motor, cardiac, and daily functional benefits in stroke survivors.     

早期踝及足趾背屈训练对脑卒中偏瘫患者异常步态的影响

目的：探讨早期踝背屈及足趾训练对脑卒中偏瘫患者异常步态的促进作用。方法：病程〈21 d的脑卒中偏瘫患者61例,随机分为观察组31例和对照组30例,均在常规脑血管病治疗基础上给予神经生理学技术治疗。观察组在治疗过程中配合踝及足趾背屈训练。训练前后分别采用Fugl-Meyer法（FMA）评定下肢运动功能和平衡能力,Barthel指数法（BI）评定下肢ADL,足印法分析步态。结果：训练3个月后,2组FMA和平衡能力积分、BI积分及步速均较治疗前明显提高,左右步幅差异明显缩小（P〈0.01）。2组间比较,观察组各项评定指标的改善程度均明显优于对照组（P〈0.01）。结论：早期配合踝及足趾背屈训练可提高脑卒中偏瘫患者步行能力,减少异常步态的发生。     

肌力训练对偏瘫步态的影响及下肢功能评定与步态分析间的相关性

目的　本文探讨了偏瘫患者在恢复期行患肢膝关节屈伸肌群肌力训练的效果 ,以及下肢功能评定与步态分析之间的相关性。方法　 5 0例脑卒中患者随机分为观察组 ( 30例 )和对照组 ( 2 0例 ) ,二组患者康复训练相同 ,观察组患者在恢复期增加患肢股四头肌、绳肌肌力训练。治疗前后分别采用Fugl Meyer法、Barthel指数法及足印法对二组患者下肢功能及步态进行分析。结果　观察组患者步态较对照组明显改善 (P<0 .0 1)、运动功能与活动能力显著提高 (P <0 .0 1)。步态的对称性与下肢运动功能、平衡功能显著相关 (r =-0 .79,-0 .71、P <0 .0 1) ,与活动能力无关 (r =-0 .2 1,P >0 .0 5 ) ;步速与下肢运动功能、平衡功能、活动能力均显著相关 (r =0 .80、0 .78、0 .76 ,P <0 .0 1)。结论　偏瘫患者在恢复期行患肢膝屈伸肌群肌力训练有助于运动功能提高、步态改善 ;通过足印法步态分析可初步了解下肢步行能力。     

Effects of exercise training programs on walking competency after stroke: a systematic review

To determine the effectiveness of training programs that focus on lower-limb strengthening, cardiorespiratory fitness, or gait-oriented tasks in improving gait, gait-related activities, and health-related quality of life after stroke. Randomized controlled trials (RCTs) were searched for in the databases of Pubmed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, DARE, Physiotherapy Evidence Database (PEDro), EMBASE, Database of the Dutch Institute of Allied Health Care, and CINAHL. Databases were systematically searched by two independent researchers. The following inclusion criteria were applied: (1) participants were people with stroke, older than 18 yrs; (2) one of the outcomes focused on gait-related activities; (3) the studies evaluated the effectiveness of therapy programs focusing on lower-limb strengthening, cardiorespiratory fitness, or gait-oriented training; and (4) the study was published in English, German, or Dutch. Studies were collected up to November 2005, and their methodological quality was assessed using the PEDro scale. Studies were pooled and summarized effect sizes were calculated. Best-evidence synthesis was applied if pooling was impossible. Twenty-one RCTs were included, of which five focused on lower-limb strengthening, two on cardiorespiratory fitness training (e.g., cycling exercises), and 14 on gait-oriented training. Median PEDro score was 7. Meta-analysis showed a significant medium effect of gait-oriented training interventions on both gait speed and walking distance, whereas a small, nonsignificant effect size was found on balance. Cardiorespiratory fitness programs had a nonsignificant medium effect size on gait speed. No significant effects were found for programs targeting lower-limb strengthening. In the best-evidence synthesis, strong evidence was found to support cardiorespiratory training for stair-climbing performance. Although functional mobility was positively affected, no evidence was found that activities of daily living, instrumental activities of daily living, or health-related quality of life were significantly affected by gait-oriented training. This review shows that gait-oriented training is effective in improving walking competency after stroke.     

Patient-cooperative control increases active participation of individuals with SCI during robot-aided gait training

Background  

Manual body weight supported treadmill training and robot-aided treadmill training are frequently used techniques for the gait rehabilitation of individuals after stroke and spinal cord injury. Current evidence suggests that robot-aided gait training may be improved by making robotic behavior more patient-cooperative. In this study, we have investigated the immediate effects of patient-cooperative versus non-cooperative robot-aided gait training on individuals with incomplete spinal cord injury (iSCI).     

脑卒中患者运动功能自动化评定研究进展

采用量表方式对脑卒中患者进行运动功能评定,存在效率低、主观性强等不足。基于传感器技术和机器学习方法的脑卒中运动功能自动化评定,可针对脑卒中患者的运动控制、平衡、步态、关节活动度等运动功能进行自动化评定,开发了许多产品。     

Activity-dependent plasticity in spinal cord injury

The adult mammalian central nervous system (CNS) is capable of considerable plasticity, both in health and disease. After spinal neurotrauma, the degrees and extent of neuroplasticity and recovery depend on multiple factors, including the level and extent of injury, postinjury medical and surgical care, and rehabilitative interventions. Rehabilitation strategies focus less on repairing lost connections and more on influencing CNS plasticity for regaining function. Current evidence indicates that strategies for rehabilitation, including passive exercise, active exercise with some voluntary control, and use of neuroprostheses, can enhance sensorimotor recovery after spinal cord injury (SCI) by promoting adaptive structural and functional plasticity while mitigating maladaptive changes at multiple levels of the neuraxis. In this review, we will discuss CNS plasticity that occurs both spontaneously after SCI and in response to rehabilitative therapies.     

Sustained prefrontal activation during ataxic gait: a compensatory mechanism for ataxic stroke?

There is accumulated evidence that cortical reorganization plays an important role in motor recovery after supratentorial stroke. However neural mechanisms underlying functional recovery of ataxia after infratentorial stroke remain unclear. We investigated cortical activations during ataxic gait in patients with infratentorial stroke to test the hypothesis that cerebral cortices were involved in compensatory mechanisms for ataxic gait. Twelve patients with infratentorial stroke (mean duration+/-S.D. from the onset: 88.3+/-44.8 days) and 11 age-matched healthy subjects participated in this study. All patients had predominant ataxia without severe hemiparesis. We measured cortical activation as assessed by task-related increase of oxygenated hemoglobin during gait on a treadmill using functional near-infrared spectroscopy. Task consisted of three repetitions of gait period alternated with rest period. In controls, cortical activations in the lateral and medial prefrontal cortex during the acceleration phase tended to be attenuated during the steady phase of the gait period while these activations were sustained throughout the gait period in ataxic patients. Repeated measures ANOVA for cortical activation revealed significant interactions (p<0.005) between phase (acceleration/steady) and group (control/stroke) in the medial and lateral prefrontal regions. These results suggest that sustained prefrontal activation during ataxic gait might be relevant to compensatory mechanisms for ataxic gait after infratentorial stroke.     

Gait training combining partial body-weight support, a treadmill, and functional electrical stimulation: effects on poststroke gait

BACKGROUND AND PURPOSE: Treadmill training with harness support is a promising, task-oriented approach to restoring locomotor function in people with poststroke hemiparesis. Although the combined use of functional electrical stimulation (FES) and treadmill training with body-weight support (BWS) has been studied before, this combined intervention was compared with the Bobath approach as opposed to BWS alone. The purpose of this study was to evaluate the effects of the combined use of FES and treadmill training with BWS on walking functions and voluntary limb control in people with chronic hemiparesis. SUBJECTS: Eight people who were ambulatory after chronic stroke were evaluated. METHODS: An A(1)-B-A(2) single-case study design was applied. Phases A(1) and A(2) included 3 weeks of gait training on a treadmill with BWS, and phase B included 3 weeks of treadmill training plus FES applied to the peroneal nerve. The Stroke Rehabilitation Assessment of Movement was used to assess motor recovery, and a videography analysis was used to assess gait parameters. RESULTS: An improvement (from 54.9% to 71.0%) in motor function was found during phase B. The spatial and temporal variables cycle duration, stance duration, and cadence as well as cycle length symmetry showed improvements when phase B was compared with phases A(1) and A(2). DISCUSSION AND CONCLUSION: The combined use of FES and treadmill training with BWS led to an improvement in motor recovery and seemed to improve the gait pattern of subjects with hemiparesis, indicating the utility of this combination method during gait rehabilitation. In addition, this single-case series showed that this alternative method of gait training--treadmill training with BWS and FES--may decrease the number of people required to carry out the training.     

稳定期慢性阻塞性肺疾病患者肺康复下肢运动训练处方的研究

目的 观察下肢运动训练对稳定期慢性阻塞性肺疾病(COPD)患者的肺功能、运动耐力及运动心肺功能的影响,同时对肺康复中运动训练的方式、强度、频度等的设定进行探索,为制定出适合中国COPD患者的肺康复运动处方提供依据.方法 选择稳定期COPD患者29例,随机分为对照组10例,训练组19例.对照组接受常规的内科药物治疗,维持日常活动量;训练组除接受常规内科药物治疗外,还接受为期8周,每周2次,每次40 min的下肢运动训练.训练方式采用下肢功率踏车训练,初始训练强度为70%最大运动负荷(WRmax),当患者能够连续2次完成预设的训练强度和时间时,以10% WRmax的梯度增加训练负荷作为下一个训练强度直至8周末.结果 经过8周的下肢运动训练,训练组患者的运动耐力指标6 min步行距离(6MWD)较训练前平均增加(45.3±27.3)m(P<0.05),WRmax增加(10.8±6.9)watt,峰值摄氧量(VO2 Peak)增加(158.9±137.3)ml/min,VO2/kg增加(2.6±2.6)ml·min-1·kg-1,无氧阈(AT)增加(93.1±91.2)ml/min,差值均具有统计学意义(P<0.01);通气指标二氧化碳生成量(VCO2)增加(102.6±177.9)ml/min(P<0.05),分钟通气量(VE)增加(5.3±4.9)L/min(P<0.01);心功能指标最大氧脉(O2 pulse)和最大心率(HRmax)较对照组显著提高(P<0.05);静态肺功能指标于训练前后未见明显变化.同时,对照组上述各组指标在8周前后均无明显变化.结论 下肢高强度运动训练可以提高稳定期COPD患者的运动耐力,改善患者在运动中的通气功能和心功能,但是对静态肺功能无明显改善作用;下肢功率踏车训练,为期8周,每周2次,每次40 min,以70% WRmax作为起始训练强度,在能连续2次完成规定的训练强度和时间的前提下,以10% WRmax为梯度递增训练强度直至8周末,这一肺康复下肢运动训练处方对于中重度COPD患者来说安全、可行,值得推广.     

Treadmill training improves fitness reserve in chronic stroke patients.

OBJECTIVE: To investigate the hypothesis that treadmill training will improve peak fitness, while lowering the energy cost of hemiparetic gait in chronic stroke patients. DESIGN: Noncontrolled exercise intervention study with repeated-measures analysis. SETTING: Hospital-based senior exercise research center. PARTICIPANTS: Twenty-three patients (mean age +/- standard deviation [SD] 67 +/- 8 yr) with chronic hemiparetic gait after remote (>6 mo) ischemic stroke. INTERVENTION: Three 40-minute sessions of treadmill exercise weekly for 6 months. MAIN OUTCOME MEASURES: Peak exercise capacity (VO2peak) and rate of oxygen consumption during submaximal effort treadmill walking (economy of gait) by open circuit spirometry and ambulatory workload capacity before and after 3 and 6 months of training. RESULTS: Patients who completed 3 months of training (n = 21) increased their VO2peak +/- SD from 15.4 +/- 2.9 mL x kg(-1) x min(-1) to 17.0 +/- 4.4 mL x kg(-1) x min(-1) (p <.02) and lowered their oxygen demands of submaximal effort ambulation from 9.3 +/- 2 mL x kg(-1) x min(-1) to 7.9 +/- 1.5 mL x kg(-1) x min(-1) (p =.002), which enabled them to perform the same constant-load treadmill task using 20% less of their peak exercise capacity (62.3% +/- 17.2% vs 49.9% +/- 19.3%, p <.002). Gains in VO2peak and economy of gait plateaued by 3 months, while peak ambulatory workload capacity progressively increased by 39% (p <.001) over 6 months. CONCLUSIONS: Treadmill training improves physiologic fitness reserve in chronic stroke patients by increasing VO2peak while lowering the energy cost of hemiparetic gait, and increases peak ambulatory workload capacity. These improvements may enhance functional mobility in chronic stroke patients.     

Electromyographic and kinematic nondisabled gait differences at extremely slow overground and treadmill walking speeds

This study compared the kinematic and electromyographic (EMG) gait patterns of able-bodied adults at natural speed in contrast to extremely slow overground and treadmill walking speeds. Kinematic and EMG data were collected at three speeds (self-selected, 0.30 m/s, and 0.20 m/s). Eighteen subjects were evaluated for trunk and lower-limb motion and EMG of five lower-limb muscles. Significant reductions were found in segmental motion between natural speed and both slower gait speeds, accompanied by an expected reduction in cadence and stride. EMG patterns at slower speeds showed changes in timing and reduced magnitudes. Phasic timing of the proximal muscles showed the most changes with predominant coactivation, whereas the distal muscles remained consistent with the pattern at natural self-selected speed. Overground versus treadmill gait patterns revealed minimal differences. Consideration of the effects of slower walking speed may help clinicians create interventions to target primary gait deficits on overground or treadmill walking.