Improved ankle and knee control with a dual-channel functional electrical stimulation system in chronic hemiplegia. A case report.

The aim of tis report is to describe the effects of a dual-channel functional electrical stimulation (FES) system applied daily as an orthotic device to the dorsiflexors and hamstrings muscles in a subject with chronic hemiparesis. Prior to the application of FES, the patient's gait was characterized by a footdrop and knee hyperextension during stance. measurements of gait performance were collected before FES application, after a conditioning period of six weeks, and following ten months of daily use. Outcomes included lower limb kinematics and temporal gait measures. The kinematic assessments indicated significant benefits for gait with the dorsiflexors and hamstrings FES, as compared to no stimulation and peroneal FES alone. In addition ot improved ankle control, knee hyperextension was reduced during stance, and the self-selected comfortable gait velocity increased following ten months of daily use. The results of this report suggest that dual-channel FES for the dorsiflexors and hamstrings muscles may affect ankle and knee control beyond that witch can be attributed to peroneal stimulation alone. The positive effects observed in this case study point to the potential of dual-channel FES as a viable treatment options in the rehabilitation of patients with similar impairments.

Quadriceps femoris muscle fatigue in patients with knee osteoarthritis.

The purpose of this study was to characterize quadriceps femoris muscle fatigue of both lower extremities in patients with knee osteoarthritis (OA). Sixty-two subjects (mean age 68.2 years, standard deviation [SD] ± 7.9 years) with knee OA participated in the study. Significantly higher knee pain was reported in the involved knee than in the contralateral knee, as determined by a visual analog scale. Significant differences were demonstrated between the lower extremities in terms of maximal voluntary isometric contraction, in favor of the less involved leg (P = 0.0001). In contrast, the degree of fatigue of the quadriceps femoris muscle, as measured by the decrement in force production following ten repeated contractions, was significantly higher in the contralateral leg (P = 0.0002). Furthermore, normalization of the fatigue results to the first contraction yielded a similar result (P < 0.0001). Similar results were noted when analysis was performed separately for subjects whose involvement was unilateral or bilateral. The results indicate that, irrespective of the initial strength of contraction, the rate of muscle fatigue in the contralateral leg is significantly higher than in the involved leg. Hypotheses for these unexpected results are suggested. Rehabilitation of patients with knee OA should focus on increasing quadriceps muscle strength and endurance for both lower extremities.

Does neuromuscular electrical stimulation enhance the effectiveness of an exercise programme in subjects with knee osteoarthritis? A randomized controlled trial.

OBJECTIVE: To determine whether neuromuscular electrical stimulation applied to the quadriceps femoris muscle will enhance the effectiveness of an exercise programme in patients with knee osteoarthritis. DESIGN: A randomized trial with parallel intervention treatment groups. SETTING: Outpatient physical therapy clinic. SUBJECTS: Fifty participants (mean age (SD) 68.9 (7.7) years) with symptomatic idiopathic knee osteoarthritis and radiographic evidence (grade ≥ II Kelgren's classification). INTERVENTIONS: Participants were randomized into one of two groups receiving 12 biweekly treatments: An exercise-only group or an exercise combined with neuromuscular electrical stimulation group (biphasic pulses, at 75 Hz and 250 µs phase duration). MAIN MEASURES: Knee pain intensity; maximal voluntary isometric contraction and voluntary activation of the quadriceps femoris muscle; measures of functional performance. RESULTS: A significant interaction effect (P = 0.01) indicated greater improvement in pain for the electrical stimulation group. The mean (SD) change in pain intensity was from 7.5 ± 2 to 5 ± 2.2 and from 7.4 ± 1.9 to 3.3 ± 2.4 in the exercise and electrical stimulation groups, respectively. A significant treatment effect was also noted for the voluntary activation of the quadriceps femoris, which increased by 22.2% in the electrical stimulation group and by 9.6% in the exercise group (P = 0.045). Significant improvements were observed in both groups in all remaining measures, with no differences between groups. CONCLUSIONS: Electrical stimulation treatment to the quadriceps femoris enhanced the effectiveness of an exercise programme in alleviating pain and improving voluntary activation in patients with knee osteoarthritis, but did not enhance its effect on muscle strength or functional performance.

Effectiveness of thermal and athermal short-wave diathermy for the management of knee osteoarthritis: a systematic review and meta-analysis.

OBJECTIVE: To assess the effectiveness of short-wave diathermy (SWD) treatment in the management of knee osteoarthritis (KOA) and to assess whether the effects are related to the induction of a thermal effect. METHODS: A systematic literature search was conducted in PubMed, CINAHL, PEDro, EMBASE, SPORTdiscus and Scholar Google. Included were trials that compared the use of SWD treatment in patients diagnosed with KOA with a control group (placebo SWD treatment or no intervention) and studies that used high-frequency electromagnetic energy (i.e., 27.12 MHz) with sufficient information regarding treatment dosage. Methodological quality of the included studies was assessed in accordance with the PEDro classification scale. A minimum of a 6/10 score was required for inclusion. RESULTS: Seven studies were included in the final analysis. Treatment protocols (dosage, duration, number of treatments) varied extensively between studies. The meta-analysis of the studies with low mean power did not favour SWD treatment for pain reduction, while the results of studies employing some thermal effect were significant. No treatment effect on functional performance measures was determined. CONCLUSION: This meta-analysis found small, significant effects on pain and muscle performance only when SWD evoked a local thermal sensation. However, the variability in the treatment protocols makes it difficult to draw definitive conclusions about the factors determining the effectiveness of SWD treatment. More research (using comparable protocols and outcome measurements) is needed to evaluate possible long-term effects of thermal SWD treatment and its cost effectiveness in patients with KOA.

Gender differences in pain perception and functional ability in subjects with knee osteoarthritis.

Background. There is no consensus regarding gender-related differences in pain intensity and functional abilities among patients with knee osteoarthritis (OA). Objective. Determine gender-related differences in pain intensity and functional ability among subjects with knee OA, as assessed by a self-report questionnaire and by performance-based tests. Methods. Sixty-three subjects with symptomatic knee pain due to OA were included in this study. The outcome measures were self-reported knee pain intensity and physical function (WOMAC), as well as three performance-based functional assessments: time up and go test, a 10-meter walk test, and stair negotiation. Independent sample t-tests were performed to determine gender differences. Level of significance was set at P ≤ 0.05. Results. Female subjects reported higher levels of knee pain and lower functional performance. In contrast, no significant gender-related differences were determined in any of the performance-based measures. Conclusion. The results indicate that the two types of functional ability measures may address different constructs of functional ability. Self-reported ability, particularly in the female subjects, may be influenced by psychological aspects associated with chronic pain. Rehabilitation programs should consider the underlying mechanisms of the patients' performance limitations in order to address the specific needs of each individual patient.

Effect of pulsed short-wave diathermy on pain and function of subjects with osteoarthritis of the knee: a placebo-controlled double-blind clinical trial.

OBJECTIVE: To examine the effects of pulsed short-wave diathermy (PSWD), delivered at an intensity sufficient to induce a thermal sensation and at an athermal intensity, in comparison with a placebo short-wave diathermy treatment, on reported pain, stiffness and functional ability and on mobility performance of patients with osteoarthritis of the knee. DESIGN: A placebo-controlled double-blind trial with sequential allocation of patients to different treatment groups. SETTING: Outpatient physiotherapy department. SUBJECTS: One hundred and three consecutive patients, mean age 73.7 (+/-6.6) years with osteoarthritis of one or both knees for at least three months. INTERVENTIONS: All participants received three 20-min-long treatments per week for three weeks. One group received PSWD with mean power of 18 W (thermal effect), one group received PSWD with mean power of 1.8 W (athermal effect), and one group received sham short-wave diathermy treatment. Patients were assessed before the initial treatment, immediately following the last treatment, and at a three-month follow-up. MAIN MEASURES: Outcome measures included the WOMAC Osteoarthritis Index, which assessed reported pain, stiffness, and functional ability, and four measures of mobility performance: Timed Get Up and Go test (TGUG), stair-climbing, stair, descending and a 3-min walk. RESULTS: A difference across time was observed for the pain and stiffness categories of the WOMAC Osteoarthritis Index (p = 0.033 and p = 0.008, respectively), with no differences between groups. No other significant differences across time or between groups were observed in any of the other measures. CONCLUSION: The findings do not demonstrate pulsed short-wave diathermy, as it is utilized in clinical settings, to be effective in the treatment of osteoarthritis of the knee.

Accuracy of reproducing hand position when using active compared with passive movement.

BACKGROUND AND PURPOSE: Evaluating proprioception is relevant to physical rehabilitation because of its significance in motor control. One method of proprioceptive testing involves having subjects either imitate or point at a joint position or movement which was presented via a passive movement. However, as the muscle spindles are subject to central fusimotor control, the proprioceptive system may be better-tuned to movements created by active muscular contraction than to passive movements. The objective of the present study was to determine whether accuracy of reproducing hand position is dependent on whether proprioceptive input is obtained via an active or a passive movement. METHOD: Thirty-nine healthy volunteers (mean age (+/- SD) 24.6 (+/- 3.6) years) participated in the study. Subjects' right hands, which were obscured from view, were acoustically guided to five targets on a digitizer tablet with either an active or passive upper extremity movement. Subjects were then asked to reproduce the targets' location by either reaching to them with the unseen hand or by use of a laser beam. Distance from target and angular deviations were calculated in both absolute and relative terms. Repeated measures analysis of variance (ANOVA) was performed for each variable followed by predetermined contrasts. RESULTS: Comparison between the active and passive conditions when reconstruction of target location was guided kinaesthetically indicates significant differences in absolute distance, range and angular deviation. The comparison when reconstruction of target location was guided visually indicates significant differences in absolute distance, absolute angle and angular deviation. CONCLUSIONS: The ability to reproduce hand position accurately is enhanced when position is encoded by active upper extremity movement compared with passive movement. The results have implications for the design of strategies for evaluating as well as treating patients with impaired proprioception and limited movement.

Quadriceps femoris muscle torques and fatigue generated by neuromuscular electrical stimulation with three different waveforms.

BACKGROUND AND PURPOSE: Neuromuscular electrical stimulation is used by physical therapists to improve muscle performance. Optimal forms of stimulation settings are yet to be determined, as are possible sex-related differences in responsiveness to electrical stimulation. The objectives of the study were: (1) to compare the ability of 3 different waveforms to generate isometric contractions of the quadriceps femoris muscles of individuals without known impairments, (2) to compare muscle fatigue caused by repeated contractions induced by these same waveforms, and (3) to examine the effect of sex on muscle force production and fatigue induced by electrical stimulation. SUBJECTS: Fifteen women and 15 men (mean age=29.5 years, SD=5.4, range=22-38) participated in the study. METHODS: A portable battery-operated stimulator was used to generate either a monophasic or biphasic rectangular waveform. A stimulator that was plugged into an electrical outlet was used to generate a 2,500-Hz alternating current. Phase duration, frequency, and on-off ratios were kept identical for both stimulators. Participants did not know the type of waveform being used. Torque was measured using a computerized dynamometer. A maximal voluntary isometric contraction (MVIC) of the right quadriceps femoris muscle set at 60 degrees of knee flexion was determined during the first session. In each of the 3 testing sessions, torque of contraction and fatigue elicited by one waveform were measured. Order of testing was randomized. Torque elicited by electrical stimulation was expressed as a percentage of average MVIC. A mixed-model analysis of variance was used to determine the effect of stimulation and sex on strength of contraction and fatigue. Bonferroni-corrected post hoc tests were used to further distinguish between the effects of the 3 stimulus waveforms. RESULTS: The results indicated that the monophasic and biphasic waveforms generated contractions with greater torque than the polyphasic waveform. These 2 waveforms also were less fatiguing. The torques from the maximally tolerated electrically elicited contractions were greater for the male subjects than for the female subjects. DISCUSSION AND CONCLUSION: Muscle torque and fatigue of electrically induced contractions depend on the waveform used to stimulate the contraction, with monophasic and biphasic waveforms having an advantage over the polyphasic waveform. All tested waveforms elicited, on average, stronger contractions in male subjects than in female subjects when measured as a percentage of MVIC.

The effect of treadmill training on the ambulation of stroke survivors in the early stages of rehabilitation: a randomized study.

The objective of this study was to compare the effects of conventional over-ground gait training with treadmill training on the restoration of gait in people with hemiparesis following a stroke. Twenty-five individuals in the early stages of rehabilitation were alternately assigned to one of two treatment groups. In addition to conventional physical therapy, the experimental group participated in 15 treadmill-training sessions in which a handrail was used for external support. The control group received the same number of equal length sessions of over-ground ambulation. Treatment effects were established by pre- and posttreatment assessment of: 1) functional walking ability, 2) walking speed, 3) stride length, 4) temporal characteristics of gait, and 5) electromyographic activity of calf muscles. Normal values were obtained from eight healthy individuals of approximately the same age as the stroke survivors. The study demonstrates that individuals following a stroke are well able to tolerate treadmill training in the early stage of their rehabilitation process without the use of a weight support apparatus. Furthermore, the findings suggest that treadmill training may be more effective than conventional gait training for improving some gait parameters such as functional ambulation, stride length, percentage of paretic single stance period, and gastrocnemius muscular activity.

Time-related changes in motor performance of the upper extremity ipsilateral to the side of the lesion in stroke survivors.

OBJECTIVE: The objective of the present study was to examine time-related changes in motor performance of daily tasks of the upper extremity ipsilateral to the side of lesion in poststroke hemiparetic patients. METHODS: Nine patients after an acute uniliteral cerebrovascular accident and 10 age-matched healthy controls were studied. Functional motor abilities of the upper extremity ipsilateral to side of lesion were examined over a 4-month time course, using validated measurement tools (Jebsen test of hand function, nine-hole peg test, and three functional activities of daily living). RESULTS: The results indicated a significant impairment in the motor function of the hand ipsilateral to the side of brain lesion in comparison with the matched extremity in control subjects. They also pointed to time-related improvement in performance speed, implying that the deterioration in the functional performance of the upper extremity on the uninvolved body side of poststroke hemiparetic patients is not static and may improve with time. The findings further suggested that the left hand of patients with an intact right cerebral hemisphere improves more than does the right hand of their peers whose left cerebral hemisphere is intact. CONCLUSIONS: Due to the small sample size and methodologic considerations, further and more extensive work is required to determine difference in improvement in motor abilities of the ipsilateral left versus the ipsilateral right upper extremities in stroke survivors.

Weight-bearing shifts of hemiparetic and healthy adults upon stepping on stairs of various heights.

OBJECTIVE: To examine and compare the effect of stepping on stairs of various heights on lower extremity weight bearing in hemiparetic patients. SETTING: Flieman Geriatric Rehabilitation Hospital, Haifa, Israel. SUBJECTS: Fifteen ambulatory hemiparetic patients following an acute cerebrovascular accident, and 16 age-matched healthy controls. INTERVENTIONS: Each subject was tested twice on two consecutive days in five weight-bearing positions which included level stance and stepping with either leg on 10-cm- and 17-cm-high steps. Data concerning weight distribution on the lower extremities were collected by two computerized forceplates. MAIN OUTCOME MEASURE: Weight borne by each foot expressed as percentage of overall body weight. RESULTS: In the attempted symmetrical level stance, the percentage of body weight borne by the paretic limb of the stroke patients was significantly lower than that of the nonparetic limb. Placing one foot on a step induced a weight shift to the foot placed on the floor regardless of step height. Weight shifting to the paretic limb was, however, significantly lower than to the nonparetic limb. Weight shifting to the nonparetic limb was significantly lower than to the corresponding limb of healthy individuals. Step height had no significant effect on weight distributions on the feet. CONCLUSIONS: Raising a foot on a step appears to be an appropriate strategy for weight shift training of stroke patients. Since weight shifting to both the paretic and nonparetic limb of stroke patients is impaired, treatment strategies should include training in weight shifting to both lower extremities.

Activation of selected trunk muscles during symmetric functional activities in poststroke hemiparetic and hemiplegic patients.

OBJECTIVE: To compare the EMG activity between the recti abdominii muscles and between the lumbar erector spinae muscles in hemiparetic and hemiplegic patients during functional symmetric trunk movements and to compare patients' EMG activity profiles with those of healthy controls. METHODS: EMG activity from the selected muscles was recorded during three symmetric and time controlled trunk exercises. Data analysis was based on values of cross correlations and of ratios between EMG activity of the bilateral corresponding muscles. RESULTS: In all groups, the highest cross correlations were obtained for both muscles when the muscles acted as prime movers. For the recti abdominii muscles, these values in the patients were comparable with those of the healthy subjects, whereas for the extensor muscles, the highest synchronous activity was displayed in healthy subjects and the lowest in hemiplegic patients. Laterality differences in the amount of EMG activity of the recti abdominii muscles were not biased towards one side. For the extensor muscles, in the controls, the activation levels were higher in the left erector spinae muscle than in the right one in two of the three exercises. Similarly, in the extensor muscles of the hemiparetic patients, activity on the paretic side was higher than on the non-paretic side in two exercises. CONCLUSIONS: In patients with a supratentorial poststroke hemiparesis or hemiplegia, bilateral corresponding axial trunk muscles co-contract during symmetric trunk activities. Synchronous activation is at its highest level during voluntary dynamic tasks and is greater in the recti abdominii than in the erector spinae muscles. For both muscles, EMG activation levels on the paretic side were not lower than on the non-paretic side. Thus, the assertion that the muscles on the paretic side are activated to a lesser extent than their counterparts on the non-paretic side during symmetric trunk movements was not confirmed.

Visual and kinesthetic control of goal-directed movements to visually and kinesthetically presented targets.

The study investigated the contribution of kinesthetic and visual input to the performance of reaching movements and identified rules governing the transformation of information between these two sensory modalities. The study examined the accuracy by which 39 subjects reproduced locations of five targets in a horizontal plane. Mode of target presentation and feedback during reproduction of a target's location was either visual, kinesthetic or a combination of both modalities. Thus, it was possible to examine performance when target presentation and reproduction involved feedback from the same sensory modality (intramodal) as well as from different sensory modalities (intermodal). Errors in target reproduction were calculated in terms of distance and systematic biases in movement extent. The major findings of the study are (1) Intramodal reproduction of a target's location on the basis of kinesthetic feedback is somewhat less accurate than intramodal reproduction on the basis of visual feedback (2) Intermodal performance is significantly less accurate than intramodal performance. (3) Accuracy of performance does not depend on the direction of information transfer between sensory modalities. (4) Intermodal performance is characterized by systematic biases in extent of movement which are dependent on the direction of information transfer between modalities. (5) When presentation of the target's location is bimodal, reproduction is adversely affected by the conflicting input. The results suggest that transformation rules, used to combine input from various sensory modalities, depend on environmental conditions and attention.

Repetitive practice of a single joint movement for enhancing elbow function in hemiparetic patients.

The primary goal of this study was to assess whether repetitive practice of flexion-extension movements of the affected elbow in hemiparetic patients enhances performance and to compare the effects of this practice mode to the effects of the physical therapy variable exercise program which is routinely applied during sessions. Subjects were 27 poststroke hemiparetic patients, residents of a rehabilitation institute, divided into an experimental (n = 15) and a control group (n = 12). The former were treated with 800 repeated elbow movements in a maximal predetermined amplitude of 80 degrees, provided in 8 equal sessions every other day. The latter received 10 min. of conventional physical therapy for the paretic upper extremity at similar time intervals. Pre- and posttreatment assessments included the bilateral measurements of kinematic variables and activation latencies of the biceps and triceps brachi muscles as well as motor and functional tests. For all criterion variables, the findings pointed to comparable improvement in both groups. It was concluded that repetitive elbow movements had no unique training effect on the kinematics of movement and on activation latencies of the primary muscles controlling elbow function in hemiparetic patients. Further, transfer of the effects of training to execution of movements towards and from the mouth was also comparable in both groups, pointing again to there being no particular advantage in using repetitive movements as a training mode for enhancement of elbow function in hemiparetic patients.

Maturation of renal tubular transport of digoxin.

Previous data have suggested an age-related increase in renal tubular secretion of digoxin in infants and children receiving long-term digoxin therapy. This phenomenon could be the result of a maturational process or secondary to chronic substrate stimulation. To investigate this question, two groups of 2-week-old paired littermate rats received intraperitoneal injections of either digoxin or an equal volume of normal saline (control) on alternate days until sacrificed at 4, 6, and 8 wk of age. An additional group of 12-wk-old rats were studied as controls. 125I-labeled digoxin uptake was measured in renal cortical slices as the cPM/mg wet tissue slice/medium ratio (S/M). Both digoxin-treated and control rats demonstrated significant age-related increments in digoxin uptake. S/M ratios at 4, 6, 8, and 12 wk in he control group were 1.34 +/- 0.06, 1.39 +/- 0.14, 1.62 +/- 0.18 and 1.93 +/- 0.23, respectively (mean +/- S.D.) (r = 0.81; P less than 0.001). S/M ratios in the digoxin-treated animals at 4, 6, and 8 wk were 1.28 +/- 0.16, 1.33 +/- 0.09, and 1.52 +/- 0.23, respectively (r = 0.50; P less than 0.025), but did not differ significantly at each age from those in the control group. 125I uptake was significantly reduced by both dinitrophenol and sodium azide, as well as by a 100% nitrogen atmosphere. These results indicate that renal tubular transport of digoxin is an age-related energy dependent process which probably is not subject to substrate stimulation.