Leg Training Research Articles

Factors influencing isometric exercise training-induced reductions in resting blood pressure.

Hypertension is a major health concern, and current recommendations for blood pressure management (lifestyle modifications and pharmacological intervention) have not been universally successful. For two decades, isometric exercise training (IET) has become established as effective at reducing in resting BP (RBP) in a short period (4-10 weeks). The most common IET modes have comprised isometric handgrip (IHG) or isometric bilateral leg (IBL) training and 4 × 2-min contractions at ∼20-50% maximal voluntary contraction with 1-5-min rest between. Although this type of exercise training could have important implications, for hypertensive patients and in preventing hypertension development, little is known about the mechanisms responsible for IET-induced RBP reductions. This uncertainty derives from a lack of understanding concerning the most effective IET programs for specific populations. Possible influential factors and mechanisms include age, sex, pre-existing disease and medication, and IET-induced adaptations in the exercising muscle and nervous system, which are discussed in this review. Designing effective IET programs may involve manipulation of exercise intensity, frequency, duration and mode, as well as consideration of yet discovered mechanisms for RBP reductions. We call for additional research designed to understand more about the mechanisms involved in IET-induced RBP reductions for maximum effectiveness.

A bilateral rehabilitation system for the lower limbs

Purpose: Bilateral and unilateral training equipment for the upper limbs facilitates rehabilitation after stroke. In this work, we tested the first device designed for bilateral training of the lower limbs. Method: Characteristics and usage of the novel MedExercise® ST device were evaluated by four healthy volunteers. A pedometer and temperature sensor were attached to the device and used to measure cadence and intensity of training, respectively. The heart rates of participants were recorded with a fingertip pulse oximeter. Thirty elderly patients assessed usability of the device and completed the survey. Results: It was shown that the device could be operated in sitting and recumbent positions. The resistance levels and range of joint motion were individually adjustable for each leg, allowing both bilateral and unilateral training. When pedals were linked together, one leg could help moving the other leg. Recording of training intensities allowed leg fitness testing, personalized exercise prescription and analysis of self-controlled training. A usability survey demonstrated positive perception of elderly patients towards the device. Conclusions: This training system has a range of useful features, which can facilitate rehabilitation of the lower limbs via early leg mobilization and self-controlled training.Implications for RehabilitationBilateral and unilateral training devices are widely used to improve the effectiveness of upper limb rehabilitation, but there is no analogous equipment available for the lower limbs.Here, we show that the MedExercise® ST training system allows independent exercise of each leg in bilateral and unilateral modes, and objective recording of training activities.Elderly patients attending the exercise rehabilitation clinic demonstrated a positive perception towards usability of this equipment.The results of this study suggest suitability of the system for optimization of lower limb rehabilitation, including early leg mobilisation and self-controlled training.

Sensitivity of sensor-based sit-to-stand peak power to the effects of training leg strength, leg power and balance in older adults

Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS peak power and related measures are sensitive to the effects of increasing leg strength, leg power and overall balance in older adults. A further aim was to compare sensitivity between sensor-based STS measures and standard clinical measures of leg strength, leg power, balance, mobility and fall risk, following an exercise-based intervention. To achieve these aims, 26 older adults (age: 70–84 years) participated in an eight-week exercise program aimed at improving leg strength, leg power and balance. Before and after the intervention, performance on normal and fast STS transfers was evaluated with a hybrid motion sensor worn on the hip. In addition, standard clinical tests (isometric quadriceps strength, Timed Up and Go test, Berg Balance Scale) were performed. Standard clinical tests as well as sensor-based measures of peak power, maximal velocity and duration of normal and fast STS showed significant improvements. Sensor-based measurement of peak power, maximal velocity and duration of normal STS demonstrated a higher sensitivity (absolute standardized response mean (SRM): ≥0.69) to the effects of training leg strength, leg power and balance than standard clinical measures (absolute SRM: ≤0.61). Therefore, the presented sensor-based method appears to be useful for detecting changes in mobility and fall risk.

Training Transfer: Scientific Background and Insights for Practical Application

Training transfer as an enduring, multilateral, and practically important problem encompasses a large body of research findings and experience, which characterize the process by which improving performance in certain exercises/tasks can affect the performance in alternative exercises or motor tasks. This problem is of paramount importance for the theory of training and for all aspects of its application in practice. Ultimately, training transfer determines how useful or useless each given exercise is for the targeted athletic performance. The methodological background of training transfer encompasses basic concepts related to transfer modality, i.e., positive, neutral, and negative; the generalization of training responses and their persistence over time; factors affecting training transfer such as personality, motivation, social environment, etc. Training transfer in sport is clearly differentiated with regard to the enhancement of motor skills and the development of motor abilities. The studies of bilateral skill transfer have shown cross-transfer effects following one-limb training associated with neural adaptations at cortical, subcortical, spinal, and segmental levels. Implementation of advanced sport technologies such as motor imagery, biofeedback, and exercising in artificial environments can facilitate and reinforce training transfer from appropriate motor tasks to targeted athletic performance. Training transfer of motor abilities has been studied with regard to contralateral effects following one limb training, cross-transfer induced by arm or leg training, the impact of strength/power training on the preparedness of endurance athletes, and the impact of endurance workloads on strength/power performance. The extensive research findings characterizing the interactions of these workloads have shown positive transfer, or its absence, depending on whether the combinations conform to sport-specific demands and physiological adaptations. Finally, cross-training as a form of concurrent exercising in different athletic disciplines has been examined in reference to the enhancement of general fitness, the preparation of recreational athletes, and the preparation of athletes for multi-sport activities such as triathlon, duathlon, etc.

Operant conditioning to increase ankle control or decrease reflex excitability improves reflex modulation and walking function in chronic spinal cord injury

Ankle clonus is common after spinal cord injury (SCI) and is attributed to loss of supraspinally mediated inhibition of soleus stretch reflexes and maladaptive reorganization of spinal reflex pathways. The maladaptive reorganization underlying ankle clonus is associated with other abnormalities, such as coactivation and reciprocal facilitation of tibialis anterior (TA) and soleus (SOL), which contribute to impaired walking ability in individuals with motor-incomplete SCI. Operant conditioning can increase muscle activation and decrease stretch reflexes in individuals with SCI. We compared two operant conditioning-based interventions in individuals with ankle clonus and impaired walking ability due to SCI. Training included either voluntary TA activation (TA↑) to enhance supraspinal drive or SOL H-reflex suppression (SOL↓) to modulate reflex pathways at the spinal cord level. We measured clonus duration, plantar flexor reflex threshold angle, timed toe tapping, dorsiflexion (DF) active range of motion, lower extremity motor scores (LEMS), walking foot clearance, speed and distance, SOL H-reflex amplitude modulation as an index of reciprocal inhibition, presynaptic inhibition, low-frequency depression, and SOL-to-TA clonus coactivation ratio. TA↑ decreased plantar flexor reflex threshold angle (-4.33°) and DF active range-of-motion angle (-4.32°) and increased LEMS of DF (+0.8 points), total LEMS of the training leg (+2.2 points), and nontraining leg (+0.8 points), and increased walking foot clearance (+ 4.8 mm) and distance (+12.09 m). SOL↓ decreased SOL-to-TA coactivation ratio (-0.21), increased nontraining leg LEMS (+1.8 points), walking speed (+0.02 m/s), and distance (+6.25 m). In sum, we found increased voluntary control associated with TA↑ outcomes and decreased reflex excitability associated with SOL↓ outcomes.

Virtual reality aided training of combined arm and leg movements of children with CP.

Cerebral palsy (CP) occurs in over 2 out of 1000 live births and can impair motor control and cognition. Our goal was to create a robotic rehabilitation environment that mimics real-life situations by allowing simultaneous exercise of upper and lower limbs. We chose to use the Lokomat as a gait robot and added a novel removable arm robot, called PASCAL (pediatric arm support robot for combined arm and leg training), that was integrated into the Lokomat environment. We also added a virtual reality (VR) environment that enables the subject to perform motivating game-like scenarios incorporating combined arm and leg movements. In this paper we summarize the design of PASCAL and present the novel virtual environment including first experimental results. The next step will be to test whether a combined application of the virtual environment and the two simultaneously working robots is feasible in healthy participants, and finally to clinically evaluate the entire system on children with CP.

Relation between balance loss in floor exercises by male gymnasts and anthropometric features and balance

This study aims at looking into the relationship between losses of balance in floor exercises performed by male gymnasts at 17 th International Bosporus Gymnastics Tournament and some of the anthropomorphic characteristics and the balance tests given under laboratory conditions. 15 male gymnasts volunteered for this research, (aged= 19.93 ± 2.98, training years12.87±3.68). In order to analyze the losses of balance in floor exercises, the floor routines were recorded by video, and each loss of balance following each gymnastic element was evaluated. Also static – dynamic balance, body weight, height, arm span, leg and torso lengths were measured. Pearson Correlation coefficient was used for analyzing the relations between the data findings. It was found that there was no statistical relation between the losses of balance in floor exercises and static-dynamic balance test results (p>0.05). Also no correlation was found between floor exercise losses of balance and number of training years, height, body weight, arm span, torso length, and leg length (p>0.05). But it was observed that there was a negative correlation between dynamic balance test and body weight (r=-0.565 p<0.05) and between static balance with closed eyes and age (r=0.582 (p<0.05). A reasonable explanation for these results are that keeping one's balance after the element in artistic gymnastics is more likely to be a result of the technical mastery.

The Effect of Maximal Leg Press Strength Training on Bilateral Deficit

The purpose of this study was to determine maximal isometric strength with bilateral and unilateral muscle contractions and investigate maximal strength training whether or not influenced on this bilateral deficit. For this reason, 34 amateur soccer player (age = 17 ± 2.51 years) were divided into three groups as bilateral training group (n=14), unilateral training group (n=10) and control group (n=10). The unilateral training group performed maximal leg press exercise using each leg unilaterally. The bilateral leg training group was performed to leg press exercise using simultaneously bilateral legs. The control group wasn't trained. The groups in training continued these resistance exercises as 1 hour a day, 3 days a week, for 12 weeks. The improvement in strength brought by training was compared as bilateral training group and unilateral training group. Bilateral deficit also was calculated between two groups. The strength in the trained limbs during training was measured in 4 th weak (after four weeks) and 12 th weak (after twelve weeks). It was determined that maximal isometric strength of two training groups was increased significantly by strength trainings (p 0.05). It was determined that strength was increased significantly for final weeks of training period (p<0.05). The other important consequence of this study was determined that maximal strength training had significant effect on bilateral deficit (p<0.05). As a consequence of this study, maximal strength trainings which involved bilateral muscle contractions were effective for reducing of bilateral deficit.

Effect of upper extremity exercise in people with COPD.

Exercise for people with COPD has focused on leg training, such as walking and cycling. The role and effectiveness of arm training has not been investigated in detail. This review was undertaken to examine the literature for the effectiveness of upper extremity exercise on arm exercise capacity and arm strength in people with COPD. Trials relating to arm endurance and strength training in COPD were located by searching electronic databases and screening the reference lists of pertinent articles. Where possible, effect sizes and 95% CI were determined and meta-analysis used. The search strategy yielded 24 articles. Unsupported arm training improved arm endurance capacity (standard mean difference [SMD] =1.25; 95% CI=0.16 to 2.66) and was the optimal mode of arm endurance training. Combined unsupported and supported arm training was also found to have a large positive effect on peak arm exercise capacity (SMD=1.27; 95% CI=0.59 to 1.94). In addition arm strength training produced moderate improvements in arm strength (SMD=0.46; 95% CI=0.10 to 0.81). This review suggests that in the short term, arm endurance training improves arm exercise capacity and arm strength training improves arm strength. Further research is required, in people with COPD, to investigate the long-term effects of arm training.

The effects of arm endurance and strength training on arm exercise capacity in people with chronic obstructive pulmonary disease

Objective: Exercise training in people with chronic obstructive pulmonary disease (COPD) is widely accepted as the cornerstone to pulmonary rehabilitation. Traditionally, exercise for people with COPD has focused on leg training, such as walking and cycling. However, the recognition that there is greater limitation for daily arm activities has attracted interest in the effectiveness of arm training.This review was undertaken to examine the literature for the effectiveness of arm endurance and strength training on arm exercise capacity in people with COPD.Methods: Trials relating to arm endurance and strength training in COPD were located by searching electronic databases and screening the reference lists of pertinent articles. Where possible, effect sizes and 95% CI were determined and meta-analysis used.Results: The search strategy yielded 24 articles. Unsupported arm training improved arm endurance capacity (standard mean difference [SMD]=1·25; 95% CI=–0·16 to 2·66) and was the optimal mode of arm endurance training. Combined unsupported and supported arm training was also found to have a large positive effect on peak arm exercise capacity (SMD=1·27; 95% CI=0·59 to 1·94). In addition arm strength training produced moderate improvements in arm strength (SMD=0·46; 95% CI=0·10 to 0·81).Conclusion: This review suggests that in the short term, arm endurance training improves arm exercise capacity and arm strength training improves arm strength. Further research is required, in people with COPD, to investigate the long-term effects of arm training and to determine the optimal training routine for improving arm tasks important for daily living.

Aerobic high intensity one and two legs interval cycling in chronic obstructive pulmonary disease: the sum of the parts is greater than the whole

The purpose of this study was to investigate whether individual leg cycling could produce higher whole body peak oxygen uptake (VO(2peak)) than two legs cycling during aerobic high intensity interval training in chronic obstructive pulmonary disease (COPD) patients. Nineteen patients trained in 24 supervised cycling sessions either by one leg training (OLT) (n = 12) or by two legs training (TLT) (n = 7) at 4 x 4 min intervals at 85-95% of peak heart rate. Whole body VO(2peak) and peak work rate increased significantly by 12 and 23% in the OLT, and by 6 and 12% in the TLT from pre- to post-training, respectively, and were significantly greater in the OLT than the TLT (P < 0.05). The present study demonstrates that one leg aerobic high intensity interval cycling is superior to two legs in increasing whole body VO(2peak), indicating a muscle rather than a cardiovascular limitation to VO(2peak) in these COPD patients.

The influence of early Initiative straight-leg raising training on postoperative rehabilitation of patients with lubar intervertebrai disc protrusion

Objective To explore the influence of early initiative straight-leg raising training on postoperative rehabilitation of patients with lubar intervertebral disc protrusionMcthods 100 lubar intervertebral disc protrusion cases received nucleus gelatinosus removal operation were randomly divided into early active training group ( n = 50 ) and routine training group ( n = 50), the former were treated by straightening and raising leg training, the latter were received routine method, the curative effect, anxiety and satisfaction were evaluated after 2 weeks operation. The incidence of backleg pain and straight-leg raising test were evaluated on the 4th and 8th week, first and second year after operation. Results In early active training group, the total effective rate was 90. 0%, the incidence of anxiety was 26.0% and the satisfication was 92.0%, while in routine group, their counterpart was 74.0%, 48.0% and 72.0%. The incidence of remnant back pain after 4 and 8 weeks, 1 and 2 years was lower than that in routine group, while the incidence of remnant skelalgia was lower after 1 and 2 years operation. The positive rate of straight-leg raising test was lower than routine group on the Second year after operation. Conclusions Early straight-leg raising training on patients with lubar intervertebral disc protrusion with nucleus gelatinosus removal operation is helpful to improve the shor and prostecdtive efficacy, anxious taanxious status and statisfaction. Key words: Rehabilitation nursing; Straight-leg raising training; Satisfaction; Remnant bacldeg pain; Lubar intervertebral disc protrusion

153. Modulation of corticomuscular coherences by proprioceptive somatomotor leg training

153. Modulation of corticomuscular coherences by proprioceptive somatomotor leg training

Modulation of corticomuscular coherences by proprioceptive somatomotor leg training

Background: Corticomuscular coherence (CMC) is a measure of the degree of coupling of electrical oscillations arising in the cerebral cortex and muscles, but its functional significance is poorly understood. Little is known about the modulation of CMC by practice. As leg training has been shown to induce cortical plasticity, it might influence functional changes mediated by CMC. It remains unknown, whether alterations of functional connectivity to the lower limb display regional specificity or rather affect the wider network of muscle control.

Performance monitoring during isotonic leg training and analysis of movement

To evaluate improvements during leg training on an isotonic leg extension system, we analyzed the modality of exercise performance by building power-angle curves for each leg. Ten subjects underwent a two-month training protocol on a leg extension device. Maximal theoretical forces were evaluated to set the protocols for each subject. Each training session was monitored in real time by the acquisition of angles and building power-angle curves for each leg during sub-maximal exercise. Maximal theoretical strength, maximal speed values and slopes between the first and last training sessions differed significantly (p<0.001). Constant monitoring of exercise performance allows physical training efficiency to be improved over time. Adequate training exercises can be devised by prompt analysis of movement by power-angle curves. The isotonic test for monitoring performance is a good solution directly correlated to isokinetic methodology.

PGC-1β is downregulated by training in human skeletal muscle: no effect of training twice every second day vs. once daily on expression of the PGC-1 family

We hypothesized that the peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) family of transcriptional coactivators (PGC-1alpha, PGC-1beta, and PRC) is differentially regulated by training once daily vs. training twice daily every second day and that this difference might be observed in the acute response to endurance exercise. Furthermore, we hypothesized that expression levels of the PGC-1 family differ with muscular fiber-type composition. Thus, before and after 10 wk of knee extensor endurance training, training one leg once daily and the other leg twice daily every second day, keeping the total amount of training for the legs equal, skeletal muscle mRNA expression levels of PGC-1alpha, PGC-1beta, and PRC were determined in young healthy men (n = 7) in response to 3 h of acute exercise. No significant difference was found between the two legs, suggesting that regulation of the PGC-1 family is independent of training protocol. Training decreased PGC-1beta in both legs, whereas PGC-1alpha was increased, but not significantly, in the leg training once daily. PRC did not change with training. Both PGC-1alpha and PRC were increased by acute exercise both before and after endurance training, whereas PGC-1beta did not change. The mRNA levels of the PGC-1 family were examined in different types of human skeletal muscle (triceps, soleus, and vastus lateralis; n = 7). Only the expression level of PGC-1beta differed and correlated inversely with percentage of type I fibers. In conclusion, there was no difference between training protocols on the acute exercise and training response of the PGC-1 family. However, training caused a decrease in PGC-1beta mRNA levels.

A Controlled Trial of the Effects of Leg Training on Breathing Pattern and Dynamic Hyperinflation in Severe COPD

The effects of training on dynamic hyperinflation in stable chronic obstructive pulmonary disease (COPD) were investigated by using a controlled study of 28 subjects with FEV(1) = 42.5 (8.3 SD)%pred and 20 matched controls [FEV(1) = 44.9 (10.4)%pred]. Training consisted of spending 45 min/day, 4 days/week on a cycle-ergometer for six weeks. Maximal inspiratory and expiratory pressures (MIP and MEP), lung volumes, and two constant-work-rate (CWR) exercise tests (low- and high-intensity) were performed. Significant (p < 0.0l) improvements in the training group were observed in MIP [+8 (12) cmH(2)O], MEP [+18 (20) cmH(2)O], and endurance to high-intensity CWR [+7(5) min], and there were significant decreases in respiratory rate and end-expiratory lung volume (EELV) during both exercise tests. At 5 min, EELV decreased 0.1(0.08) L and 0.31(0.13) L and at end of exercise, EELV decreased by 0.09(0.07) L and 0.15(0.11) L respectively, for the moderate- and high-intensity tests. Dyspnea also decreased significantly at both exercise intensities. No changes were observed in the control group. Increased endurance showed independent significant (p < 0.05) correlation with changes in EELV, leg fatigue, and MEP. EELV changes showed a significant negative correlation with resting inspiratory capacity. We conclude that exercise training has beneficial effects on respiratory pattern and dynamic hyperinflation that may partially explain the reduction in dyspnea and the improvement in exercise tolerance.

Electrical Stimulation Alters FMD and Arterial Compliance in Extremely Inactive Legs

The main aim of the study was to assess the effect and time course of 4 wk of electrically induced leg training on arterial compliance and endothelial function. Six spinal cord-injured (SCI) individuals participated in 4 wk of daily one-leg functional electrical stimulation (FES) training for 30 min per session. Eight able-bodied individuals served as a control group (C) and were tested on one occasion. Echo Doppler measurements were performed before the FES training and after 1, 2, and 4 wk of training to measure vascular characteristics of femoral artery (FA), brachial artery (BA), and carotid artery (CA). Baseline arterial compliance of FA (SCI: 0.0185 +/- 0.063 mm2 x mm Hg(-1); C: 0.066 +/- 0.017 mm2 x mm Hg(-1), P = 0.001) and CA (SCI: 0.073 +/- 0.02 mm2 x mm Hg(-1); C: 0.102 +/- 0.02 mm2 x mm Hg(-1), P = 0.02) was significantly decreased in SCI. Baseline endothelial function in the leg was significantly enhanced in SCI compared with C (SCI: 11 +/- 1.3%; C: 7.9 +/- 0.9%, P = 0.001). No differences between the groups were found for arterial compliance and endothelial function in the arm. Vascular changes after FES training showed an increase in arterial compliance (significant at week 4, P < 0.05) and a decrease in FMD response (significant at weeks 2 and 4, P < 0.05) in the FA of the trained leg only, with no changes evident in the other arteries examined. Daily electrically induced training of an extremely deconditioned leg appears to enhance arterial compliance in the femoral artery and may normalize endothelial function.

Antioxidant enzyme activity is up-regulated after unilateral resistance exercise training in older adults

Cellular antioxidant capacity and oxidative stress are postulated to be critical factors in the aging process. The effects of resistance exercise training on the level of skeletal muscle oxidative stress and antioxidant capacity have not previously been examined in older adults. Muscle biopsies from both legs were obtained from the vastus lateralis muscle of 12 men 71 ± 7 years of age. Subjects then engaged in a progressive resistance exercise-training program with only one leg for 12 weeks. After 12 weeks, the nontraining leg underwent an acute bout of exercise (exercise session identical to that of the trained leg at the same relative intensity) at the same time as the last bout of exercise in the training leg. Muscle biopsies were collected from the vastus lateralis of both legs 48 h after the final exercise bout. Electron transport chain enzyme activity was unaffected by resistance training and acute resistance exercise ( p < 0.05). Training resulted in a significant increase in CuZnSOD (pre—7.2 ± 4.2, post—12.6 ± 5.6 U·mg protein −1; p = 0.02) and catalase (pre—8.2 ± 2.3, post—14.9 ± 7.6 μmol·min −1·mg protein −1; p = 0.02) but not MnSOD activity, whereas acute exercise had no effect on the aforementioned antioxidant enzyme activities. Furthermore, basal muscle total protein carbonyl content did not change as a result of exercise training or acute exercise. In conclusion, unilateral resistance exercise training is effective in enhancing the skeletal muscle cellular antioxidant capacity in older adults. The potential long-term benefits of these adaptations remain to be evaluated.

2A2-33 理学療法士の養成を支援する下肢ロボットの膝関節トルクモデルの検討(講演,福祉ロボットII)

Repeated training of manual contact with joint which has problems is meaningful for students becoming physical therapist (PT). However, they have less opportunities of such training. First, a prototype of training leg robot that can simulate knee joint movement was developed. This leg robot has the potential as a new teaching material for PT students. Second, to make some model of human knee joint torque, authors measured human knee joint torque, assumed simple model of joint torque and carried out fitting.