A comparison of uniform patterned and eutrophic electrotherapies in a clinical procedure of rehabilitation of some movements in the arthritic hand

The relative effectiveness of two different electrotherapies for hand rehabilitation was measured in 18 patients with muscle atrophy associated with rheumatoid arthritis, three of whom acted as controls and receiving no electrotherapy during the course of the trial. Both forms of electrotherapy were applied for between one and three hours each day for ten weeks. In the first electrotherapy, the stimuli were presented in a uniform pattern at a frequency of 10 stimuli/second (10 Hz). The electrotherapy for comparison (eutrophic electrotherapy) reproduced as stimuli the natural action potential firing pattern of a fatigue resistant motor unit in the first dorsal interosseus (1 st DI) of a normal hand.

Comparison was based on the relative improvement during and following 10 weeks of electrotherapy, with the two patterns of electrotherapy in seven different parameters of hand function: angular deviation at 1 st MCP joint in ulnar drift; hand grip strength; pulp-to-pulp pinch strength; key pinch strength; button-unbutton test; the maximal voluntary force 1 st DI could produce when acting isometrically; and in abduction, the endurance shown by 1 st DI in generating such force.

In all the parameters measured, eutrophic elecrotherapy was seen to be significantly more effective than a uniform patterned electrotherapy of 10 Hz. The greatest comparative effect of eutrophic electrotherapy was seen on endurance in force generation by 1 st DI and on hand grip strength, and the least on the reduction of the angular deviation of ulnar drift.

Electrotherapeutic rehabilitation of the quadriceps in elderly osteoarthritic patients: a double blind assessment of patterned neuromuscular stimulation

Recent studies, in combination with advances in modern electronics, suggest a role for electrotherapy in reversing muscle wasting. However, its effects on human subjects are not always clear-cut. The authors propose that conventional uniform frequency stimulation may deprive the muscle of adaptive information normally encoded in the nonuniform discharge of its motoneuron. This hypothesis was tested in a double blind control trial by stimulating the quadriceps femoris (QF) of elderly subjects with osteoarthritis of the knee. A stimulation pattern replicating that occurring in a normal, fatigued QF motor unit (patterned neuromuscular stimulation) was compared with uniform stimulation of the same mean frequency and random pattern stimulation (created by shuffling the order of the interpulse intervals in the replicated stimulus train). A'sham' stimulation protocol provided an effective placebo. Subjects were assessed at the level of impairment (muscle strength, endurance and cross-sectional area), disability (timed 10-metre walk, timed sit-to-stand) and handicap (part II of the Nottingham Health Profile).

Following stimulation, some descriptive improvements in outcome measures were observed in favour of PNMS, particularly in functional tests such as walking speed and sit-to-stand time. No stimulation pattern emerged as being significantly better than another, although statistically significant ( p ≤ 0.05) differences between individual stimulation patterns were observed at a number of assessment weeks.

An Electrotherapy Based on the Natural Sequence of Motor Unit Action Potentials: A Laboratory Trial

An electrotherapy based on a computer analysis of results obtained by analytical electromyography has been put to laboratory trial. Twenty-seven normal subjects received comparative regimes of electrotherapy each of which occupied three continuous hours each day for seven weeks. A comparison of the effectiveness on increasing fatigue resistance to voluntary effort of the first dorsal interosseus in the right, dominant hand was made. All electrotherapies employed had a mean frequency of stimulation of approximately 10Hz. The difference between them was found in the changes of pattern of stimulation which was exactly based on the changing patterns of discharge of slow motor units in normal muscle as it was progressively fatigued. The ability of the electrotherapies to induce fatigue resistance of the muscle was directly related to the extent of fatigue of the motor unit from which the pattern of discharge, which formed the basis of the technique, had been extracted.

Electrotherapies with patterns randomized from naturally occurring patterns are shown to be without effect on increasing the fatigue resistance of normal muscle. The significance of the results from the points of view of rehabilitation and of signal analysis are discussed.

Neuromuscular stimulation of the quadriceps muscle after hip fracture: a randomized controlled trial

OBJECTIVE

To study the feasibility and effect of neuromuscular stimulation on recovery of mobility after surgical fixation for hip fracture.

DESIGN

Double-blind study with stratified randomization.

SETTING

Home-based rehabilitation program.

PARTICIPANTS

Twenty-four women over the age of 75 years with hip fracture.

INTERVENTIONS

Neuromuscular or placebo stimulation of the quadriceps muscle of the fractured leg, applied for 3 hours a day, for 6 weeks, commencing 1 week after surgery.

MAIN OUTCOME MEASURES

Recovery of walking speed and ability, postural stability, lower-limb muscle power, and pain at 7 and 13 weeks after surgery.

RESULTS

Women in the neuromuscular stimulation group showed faster recovery of mobility. Of the women receiving stimulation, 9 of 12 recovered their prior levels of indoor mobility ability by 13 weeks compared with 3 of 12 in the placebo group (Fisher exact test, P=.046). There were no differences in recovery of walking speed in the first 7 weeks, but women in the stimulation group had greater recovery between 7 and 13 weeks (mean difference=-.13m/s; 95% confidence interval, -.23 to -.01).

CONCLUSIONS

Neuromuscular stimulation at home is feasible and may be effective in speeding recovery of mobility after surgical fixation of hip fracture.

An evaluation of a new pattern of electrical stimulation as a treatment for urinary stress incontinence: a randomized, double-blind, controlled trial

OBJECTIVE

To evaluate a new pattern of electrical of electrical stimulation as a treatment for stress incontinence.

DESIGN

A randomized, double-blind, controlled trial.

SETTING

The study took place on three clinical sites.

SUBJECTS

Patients (n = 27) with urodynamically proven stress incontinence recruited via consultant referral.

INTERVENTIONS

Patients were randomly allocated to one of two groups: the new pattern of stimulation or sham stimulation.

MAIN OUTCOME MEASURES

Patients were assessed pre, mid and post treatment using: perineometry, digital assessment and pad testing. The following were only used pre and post treatment: seven-day frequency/volume chart, SF-36, the Incontinence Impact Questionnaire and the Urogenital Distress Inventory.

RESULTS

No significant between-group differences were highlighted except when quality of life was assessed with the Urogenital Distress Inventory (p = 0.01). A significant reduction in scores was observed in the stimulation group (p = 0.03) However, improvements were seen in both the strength and endurance characteristics of the pelvic floor musculature, although these changes were not translated into a reduction in symptoms.

CONCLUSION

Although promising, the improvement in pelvic floor function did not result in a reduction in symptoms in all patients. Further research is required to investigate the effects of the new stimulation in combination with pelvic floor exercises and to compare the new stimulation pattern with existing forms of electrical stimulation.

Electrical stimulation as a treatment for stress incontinence

Much research has been conducted into the use of electrical stimulation to restore function in weak/atrophied muscle and it is used widely in the field of muscle rehabilitation. As stress incontinence is a condition which is the result of pelvic floor muscle weakness, it is thought that the symptoms of this condition may be alleviated once the strength and endurance characteristics of this muscle group have been improved. Many studies have been conducted to evaluate the efficacy of various types of electrical stimulation, although definitive conclusions have yet to be drawn. Current forms of electrical stimulation for stress incontinence involve the use of uniform frequencies. In animal studies this type of stimulation has been shown to have drawbacks that are unacceptable when trying to rehabilitate muscle. Consequently, there is a need to develop more physiological patterns of stimulation that will enhance both strength and endurance characteristics without causing premature fatigue.

The use of patterned neuromuscular stimulation to improve hand function following surgery for ulnar neuropathy

A 60-year-old man with wasting and weakness of the right hand following ulnar nerve entrapment at the elbow was referred for electrotherapy. An ulnar nerve transposition had been performed 2 years previously. This had produced some improvement in nerve conduction without significantly improving hand muscle function. The right first dorsal interosseous muscle (FDI) was stimulated for 4 hours per day over a 6-week period with a stimulus pattern replicating the discharge of a single motor unit from a healthy, fatigued FDI (patterned neuromuscular stimulation or PNMS). The response was assessed using a single case design. Significant improvements in the strength and fatigue resistance of the FDI were observed, associated with improvements in general hand function. PNMS may be useful in restoring hand function in patients with muscle atrophy following entrapment neuropathy.

Rehabilitation of Atrophied Muscle in the Rheumatoid Arthritic Hand: A Comparison of Two Methods of Electrical Stimulation

This study compares the effectiveness of two therapeutic electrotherapies which result in plastic adaptation in the atrophied muscle of rheumatoid arthritic hands. The natural discharge pattern of a fatigue-resistant motor unit (eutrophic electrotherapy) was more effective than a uniform 10 Hz electrotherapy. It was concluded that uniform 10 Hz electrotherapy ignored the information carried in the motor unit action potential spike train, which was the signal inducing rapid and behaviourally effective plastic adaptation.