The effect of cooling on muscle co-ordination in spasticity: assessment with the repetitive movement test.

PURPOSE: Cooling muscles might produce a temporary reduction of spasticity. This study investigated muscle co-ordination in spasticity under the influence of cooling. METHODS: A repetitive movement (RM-) test of the ankle was used, while measuring the angle and surface-electromyography (EMG) of the m. tibialis anterior and m. triceps surae. Ensemble averaging provided quantified measures of muscle activation. Sixteen patients with spasticity in their lower extremity due to stroke or spinal cord injury participated in the study. Physical examination and the RM-test was done before and after cooling the m. triceps surae for 20 minutes by coldpacks. RESULTS: The results show that Achilles hyperreflexia and clonus were abolished in all, and all but one patient, respectively. The EMG of the m. triceps surae, acting as a prime mover, was increased (p = 0.028). However, this improved muscle co-ordination resulted in just a slightly increased active range of motion (less than 2 degrees at p = 0.049). CONCLUSION: Apparently, the increase in excitability of the alpha motoneuron pool in voluntary movements of patients with spasticity is not followed by an improvement in the ability to move.

Forced use of the upper extremity in chronic stroke patients: results from a single-blind randomized clinical trial.

BACKGROUND AND PURPOSE: Of all stroke survivors, 30% to 66% are unable to use their affected arm in performing activities of daily living. Although forced use therapy appears to improve arm function in chronic stroke patients, there is no conclusive evidence. This study evaluates the effectiveness of forced use therapy. METHODS: In an observer-blinded randomized clinical trial, 66 chronic stroke patients were allocated to either forced use therapy (immobilization of the unaffected arm combined with intensive training) or a reference therapy of equally intensive bimanual training, based on Neuro-Developmental Treatment, for a period of 2 weeks. Outcomes were evaluated on the basis of the Rehabilitation Activities Profile (activities), the Action Research Arm (ARA) test (dexterity), the upper extremity section of the Fugl-Meyer Assessment scale, the Motor Activity Log (MAL), and a Problem Score. The minimal clinically important difference (MCID) was determined at the onset of the study. RESULTS: One week after the last treatment session, a significant difference in effectiveness in favor of the forced use group compared with the bimanual group (corrected for baseline differences) was found for the ARA score (3.0 points; 95% CI, 1.3 to 4.8; MCID, 5.7 points) and the MAL amount of use score (0.52 points; 95% CI, 0.11 to 0.93; MCID, 0.50). The other parameters revealed no significant differential effects. One-year follow-up effects were observed only for the ARA. The differences in treatment effect for the ARA and the MAL amount of use scores were clinically relevant for patients with sensory disorders and hemineglect, respectively. CONCLUSIONS: The present study showed a small but lasting effect of forced use therapy on the dexterity of the affected arm (ARA) and a temporary clinically relevant effect on the amount of use of the affected arm during activities of daily living (MAL amount of use). The effect of forced use therapy was clinically relevant in the subgroups of patients with sensory disorders and hemineglect, respectively.

Measurement of the effect of a bolus dose of intrathecal baclofen by a repetitive movement test.

We assessed the repetitive movement (RM) test for measuring the effect of a trial bolus dose of intrathecal baclofen on spasticity. The RM test measures passive range of motion (ROM) by electrogoniometry and stretch reflex activity (SRA) of the flexors and extensors of the knee and ankle by surface electromyography. The SRA has a dynamic component (dynamic stretch reflex, DSR) and a tonic component (tonic stretch reflex, TSR). Four hypotheses were formulated: (a) RM results show a negative relationship between SRA and ROM; (b) values on the RM test are correlated with clinical scores of tonus and spasticity; (c) RM results show a reduction in SRA after administration of the clinically optimal dose of baclofen; and (d) RM results show a dose-dependent effect of intrathecal baclofen on SRA. Twenty-four patients were selected because they had impairments and disabilities caused by intractable spasticity. A bolus of baclofen was administered with incremental doses (25-150 micrograms) until an optimal effect or no effect was obtained. The main outcome measures were RM test and clinical assessments of the Ashworth and spasm score. The results were (a) For the ankle a negative correlation was found between ROM and TSR of the flexor and extensors; for the knee a significant negative correlation was found only with the DSR of the biceps femoris. (b) A positive correlation was found between the Ashworth score and TSR of the extensors and between the spasm score and DSR and TSR of the gastrocnemius muscle. (c) Significant differences were found between baseline measurements and the optimal dose of baclofen for all measures. (d) A significant dose-dependent effect of intrathecal baclofen on the level of SRA was observed. The RM test is thus a useful clinical tool for objectively measuring the effect of intrathecal baclofen administration on spasticity in patients with an upper motor neuron syndrome.

Measurement of impaired muscle function of the gastrocnemius, soleus, and tibialis anterior muscles in spastic hemiplegia: a preliminary study.

Based on the results of several electrodiagnostic and biomechanical studies, the following classification of muscle dysfunction in spastic hemiplegia is proposed: changes in muscle activation (excess symptoms, e.g., spasticity, and deficit symptoms, e.g., paresis); changes in muscle stiffness; and changes in muscle length. The clinical significance of this classification is that different types of muscle dysfunction might require specific treatment. The authors have developed techniques to measure quantitatively each type of muscle dysfunction: free frequency repetitive movement (FFRM) and torque angle diagram (TAD). Surface EMGs of tibialis anterior, gastrocnemius, and soleus muscle are recorded during active (FFRM) and passive (TAD) ankle movements. EMG data are converted to parameters for abnormal muscle activation (excess and deficit symptoms). Parameters for muscle stiffness and muscle length are derived from the hysteresis curve of the TAD. This article describes the measurements and the results of a validation study. For the validation study, four hypotheses were formulated: 1) in nonimpaired control subjects, parameters expressing abnormal muscle activation are low; 2) in hemiplegic subjects, differences between the affected and the unaffected sides will be found for all types of parameters; 3) after local anaesthesia of the tibial nerve on the hemiplegic side, excess symptoms will decrease, while muscle stiffness remains unchanged; and 4) despite a uniform gait pattern, between-subject differences can be detected with regard to muscle activation, stiffness, and length. The first hypothesis was tested and confirmed in two controls; the remaining three were tested and confirmed in ten hemiplegic subjects (mean age 47.7 yrs, mean time since onset 10.7 yrs). However, the level of co-contraction of the gastrocnemius muscle was low, probably indicating that the clinical significance of this phenomenon might be limited. The results support the validity of the proposed classification and measurements.

A criterion for stability of the motor function of the lower extremity in stroke patients using the Fugl-Meyer Assessment Scale.

A test-retest reproducibility study was performed to define a criterion for stability as opposed to change of motor function of the lower extremity in stroke patients. Forty-nine patients with stroke were examined twice by the same physiotherapist, using the Fugl-Meyer Assessment Scale. The interval between both measurements was three weeks. The mean differences between the first and the second measurement were small, with 0.04 points for the lower extremity scale and 0.92 points for the balance scale, respectively. Intraclass correlation coefficient for the lower extremity scale was 0.86, and 0.34 for the balance scale. The standard error of measurement for each scale was 1.76 and 1.17 points, respectively. The standard error of measurement can be transformed in an 'error threshold', which is a criterion to differentiate real changes from changes due to chance variation or measurement error. As the absence of real change is a parameter for stability, a change of less than 5 points for the lower extremity scale and of less than 4 points for balance confirms stability of motor function.

Diagnostic blocks of the tibial nerve in spastic hemiparesis. Effects on clinical, electrophysiological and gait parameters.

The value of a diagnostic block (DB) of the tibial nerve in 17 hemiparetic patients with gait disturbances was investigated. The purpose of this study was to find instruments that help to select patients who will benefit from a long lasting peripheral nerve block. The manually elicited ankle clonus and its abolition after injection of a local anaesthetic appeared to be a useful clinical test for the efficacy of DB. Electrophysiological tests proved valuable when DB failed to produce clinical effects. With a substantial number of blocked nerve fibres walking velocity did not deteriorate. Transient disturbances in sensation can be regarded as unwanted side effects that might adversely affect the walking ability. From the different aspects of gait an improved heelcontact demonstrated the functional gain in patients with a dynamic equinus foot. To differentiate between a dynamic equinus foot and fixed contractures, we recommend the use of a fast acting local anaesthetic for diagnostic nerve blocks.

The effect of the Swedish Back School in chronic idiopathic low back pain. A prospective controlled study.

A prospective controlled study of the effect of the Swedish Back School in chronic idiopathic Low Back Pain was conducted. Forty-eight patients entered the study. There were no significant pre-treatment differences between the experimental group members who attended the four lessons of the Back School, and the control group who received four detuned shortwave applications to the low back. Forty-three patients (21 in the experimental and 22 in the control group) completed the study. Subjects were repeatedly tested for one year. The following assessments were made: 1) subjective scores of pain and functional capacity, and 2) objective measurements of spinal mobility. After one year, no statistically significant differences between the two groups were observed. Given the proven efficacy of the Back School in (sub)acute Low Back Pain, it should be administered when it is most beneficial, i.e. in the early phase of Low Back Pain.

Effect of EMG feedback on paretic muscles and abnormal co-contraction in the hemiplegic arm, compared with conventional physical therapy.

The effectiveness of EMG feedback in hemiparetic patients with an impaired arm and hand function was compared with conventional physical therapy in 18 patients, who were assigned to two groups. EMG feedback in the experimental group (n = 9) was confined to augmenting the reduced muscle activity in one proximal and one distal agonist, and to decreasing the excessive activity in one proximal antagonist and in two distal muscle groups. The control group (n = 9) was treated with conventional physical therapy. Overall duration for both treatments was 2 1/2 moths, which included 28 sessions of one hour, three times a week. Major differences in the effect of EMG feedback were found in abnormal co-contractions as compared with reduced muscle activity in agonists. The most prominent effect was found at the end of the EMG feedback training in abnormal co-contractions. Several days after ending the EMG feedback a decrease in abnormal co-contractions in the exclusively trained muscles could still be demonstrated, compared with abnormal co-contractions in untrained muscles and abnormal co-contractions in muscles treated with conventional physical therapy. However, part of the effect was lost. By contrast, intensive EMG feedback therapy had no specific effect on proximal and distal agonists of the hemiplegic arm, when compared with conventional physical therapy of a long duration. The performance of isolated voluntary movements, the occurrence of pathological associated movements and the function of the arm and the hand were not affected by the EMG feedback therapy, or by conventional physical therapy.

Objectivity and repeatability of measurements in low back pain.

A set of measurements for the quantification of low back pain was tested on 48 subjects suffering from idiopathic low back pain. Measurements were performed according to a repeated latin square model. Carry-over effects were found to be insignificant. Inter- and Intraobserver errors were small in proportion to the contribution of the subjects to the total variance of the variables indicating a good objectivity and repeatability of the test. Calculation of sum scores from similar questions, e.g. total pain score from six pain variables, permitted a further reduction of experimental errors.