Differences in Rheobase and Chronaxie between the Paretic and Non-Paretic Sides of Hemiplegic Stroke Patients: a Pilot Study

Neuromuscular disorders in women and men with spinal cord injury are associated with changes in muscle and tendon architecture

OBJECTIVE

The present study aimed to determine the association between neuromuscular function, motor function impairment, and muscle and tendon structures in individuals with spinal cord injury (SCI) compared to a control (non-disabled) population.

DESIGN

A cross-sectional study with a control group.

SETTING

Center of Adapted Sports Training and Special Physical Education.

PARTICIPANTS

Fifteen individuals with SCI and motor function impairments participated in the study. A paired non-disabled group was recruited for comparison.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Muscle (biceps brachii, rectus femoris, vastus lateralis, vastus medialis, and tibialis anterior) and tendon (quadriceps and patellar tendons) structures were assessed by ultrasound imaging (thickness, pennation angle, fascicle length, and echogenicity). Neuromuscular electrophysiological disorders were also assessed using electrodiagnosis techniques (stimulus non-responsivity and chronaxie) in the same muscles.

RESULTS

Except for the biceps brachii muscle, muscle thickness, pennation angle, and fascicle length were lower (p < 0.01) while echogenicity and chronaxie were greater (p < 0.01) in SCI participants. The SCI participants had a higher prevalence of neuromuscular electrophysiological disorders for all muscles, except the biceps brachii.

CONCLUSION

Neuromuscular disorders occur in association with muscle and tendon maladaptation in individuals with chronic SCI. A higher prevalence of electrophysiological disorders suggests an acquired polyneuromyopathy for muscles with motor function impairment even though the muscle was innerved, in addition to widespread muscle atrophy.

Influence of leg length discrepancy on balance and gait in post-stroke patients: a correlational study

Background

A frequent complaint by stroke patients presenting for physiotherapy was perceived shortness of the affected lower limb and inability to weight bear onto the affected side. So, the present study aimed to evaluate influence of limb length discrepancy (LLD) on balance and gait parameters in patients with stroke.

Subjects and methods

Twenty participants were recruited based on the inclusion and exclusion criteria and were divided into two groups group A (LLD ≤ 1 cm) and group B (LLD > 1 cm). Postural sway was measured under wide base eyes open, wide base eyes closed, narrow base eyes open, and narrow base eyes closed conditions. Weight-bearing asymmetry and functional balance were assessed using the percentage body weight asymmetry and Berg balance scale. Also, step leg ratio and 10-M walk test was used to assess gait parameters.

Results

Intergroup comparison of postural sway exhibited a significant difference between groups in the AP direction in wide-based eyes open (WBEO), wide-based eyes closed (WBEC), narrow-based eyes open (NBEO), and narrow-based eyes closed (NBEC) conditions whereas only in NBEC condition in mediolateral direction; with group B (LLD > 1 cm) displaying a greater mean postural sway in all the conditions. The correlation of LLD with postural sway showed a significant positive correlation within AP direction under all the conditions and in WBEC and NBEC conditions in mediolateral direction. Intergroup comparison of step length ratio (SLR) showed a statistical difference between groups, and a negative correlation was found between LLD and SLR. A negative correlation was also seen between percentage weight-bearing asymmetry (PWBA) and speed as well as Berg’s balance scale (BBS), and a positive correlation was observed between BBS and speed.

Conclusion

Leg length discrepancy results in a significant decrease in balance control in the sagittal and frontal planes in patients with stroke. It also adds to the asymmetries in their gait. Therefore, LLD should be considered as a factor for balance and gait asymmetries in post-stroke patients.

Neuromuscular Electrical Stimulation for Treatment of Muscle Impairment: Critical Review and Recommendations for Clinical Practice

Purpose: In response to requests from physiotherapists for guidance on optimal stimulation of muscle using neuromuscular electrical stimulation (NMES), a review, synthesis, and extraction of key data from the literature was undertaken by six Canadian physical therapy (PT) educators, clinicians, and researchers in the field of electrophysical agents. The objective was to identify commonly treated conditions for which there was a substantial body of literature from which to draw conclusions regarding the effectiveness of NMES. Included studies had to apply NMES with visible and tetanic muscle contractions. Method: Four electronic databases (CINAHL, Embase, PUBMED, and SCOPUS) were searched for relevant literature published between database inceptions until May 2015. Additional articles were identified from bibliographies of the systematic reviews and from personal collections. Results: The extracted data were synthesized using a consensus process among the authors to provide recommendations for optimal stimulation parameters and application techniques to address muscle impairments associated with the following conditions: stroke (upper or lower extremity; both acute and chronic), anterior cruciate ligament reconstruction, patellofemoral pain syndrome, knee osteoarthritis, and total knee arthroplasty as well as critical illness and advanced disease states. Summaries of key details from each study incorporated into the review were also developed. The final sections of the article outline the recommended terminology for describing practice using electrical currents and provide tips for safe and effective clinical practice using NMES. Conclusion: This article provides physiotherapists with a resource to enable evidence-informed, effective use of NMES for PT practice.

Stimulus electrodiagnosis and motor and functional evaluations during ulnar nerve recovery

BACKGROUND:

Distal ulnar nerve injury leads to impairment of hand function due to motor and sensorial changes. Stimulus electrodiagnosis (SE) is a method of assessing and monitoring the development of this type of injury.

OBJECTIVE:

To identify the most sensitive electrodiagnostic parameters to evaluate ulnar nerve recovery and to correlate these parameters (Rheobase, Chronaxie, and Accommodation) with motor function evaluations.

METHOD:

A prospective cohort study of ten patients submitted to ulnar neurorrhaphy and evaluated using electrodiagnosis and motor assessment at two moments of neural recovery. A functional evaluation using the DASH questionnaire (Disability of the Arm, Shoulder, and Hand) was conducted at the end to establish the functional status of the upper limb.

RESULTS:

There was significant reduction only in the Chronaxie values in relation to time of injury and side (with and without lesion), as well as significant correlation of Chronaxie with the motor domain score.

CONCLUSION:

Chronaxie was the most sensitive SE parameter for detecting differences in neuromuscular responses during the ulnar nerve recovery process and it was the only parameter correlated with the motor assessment.

Differences in strength-duration curves of electrical diagnosis by physiotherapists between DJ-1 homozygous knockout and wild-type mice: a randomized controlled pilot trial

[Purpose] Strength-duration (SD) curves are used in electrical diagnosis by physiotherapists to confirm muscle degeneration. However, the usefulness of SD curves in comparing muscle degeneration in DJ-1 homozygous knockout (DJ-1^−/−) and wild-type mice (DJ-1^+/+) is not yet fully understood. The electrical properties of the gastrocnemius muscles of DJ-1^−/− and DJ-1^+/+ mice were compared in the current study. [Subjects and Methods] The electrode of an electrical stimulator was applied to the gastrocnemius muscle to measure the rheobase until the response of contractive muscle to electrical stimulation became visible in mice. [Results] The rheobase of DJ-1^−/− mice showed a significant increase in a time-dependent manner, compared to that of DJ-1^+/+ mice. [Conclusion] These results demonstrate that the DJ-1 protein may be implicated in the regulation of neuromuscular activity of gastrocnemius muscles of mice.

Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study

[Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds.

Effects of conventional overground gait training and a gait trainer with partial body weight support on spatiotemporal gait parameters of patients after stroke

[Purpose] The purpose of this study was to confirm the effects of both conventional overground gait training (CGT) and a gait trainer with partial body weight support (GTBWS) on spatiotemporal gait parameters of patients with hemiparesis following chronic stroke. [Subjects and Methods] Thirty stroke patients were alternately assigned to one of two treatment groups, and both groups underwent CGT and GTBWS. [Results] The functional ambulation classification on the affected side improved significantly in the CGT and GTBWS groups. Walking speed also improved significantly in both groups. [Conclusion] These results suggest that the GTBWS in company with CGT may be, in part, an effective method of gait training for restoring gait ability in patients after a stroke.

A Pilot Study on Pain and the Upregulation of Myoglobin through Low-frequency and High-amplitude Electrical Stimulation-induced Muscle Contraction

[Purpose] It is well known that, in both in vivo and in vitro tests, muscle fatigue is produced by severe exercise, electrical stimulation, and so on. However, it is not clear whether or not low-frequency and high-amplitude modulation specifically affects serum myoglobin or urine myoglobin. The purpose of the present study was to determine the effect of low-frequency and high-amplitude modulation on serum myoglobin and urine myoglobin. [Methods] The study used whole blood samples and urine produced over 24 hours from the thirteen healthy subjects. [Results] There was a significant increase in serum myoglobin following electrical stimulation at a frequency of 10 Hz compared with the control group. Furthermore, within 24 hours, urine myoglobin also showed a significant increase for the test volunteers subjected to electrical stimulation at the 10 Hz frequency compared with the control group. However, there were no significant differences in the concentrations of hematologic results in subjects treated with electrical stimulation. [Conclusion] These results suggest that increased myoglobin related to muscle fatigue from electrical stimulation, particularly with a current of 10 Hz combined with a high-amplitude, may be partially related to increased muscle damage.

Waveform Analysis of the Brachial-ankle Pulse Wave Velocity in Hemiplegic Stroke Patients and Healthy Volunteers: A Pilot Study

[Purpose] Brachial-ankle pulse wave velocity (BaPWV), which has been reported as an index of arterial stiffness, is very closely related to cardiovascular risk factors. A high BaPWV indicates high cardiovascular risk. However, BaPWV and pressure waveforms after stroke are not fully understood. [Methods] BaPWV was measured in thirty-two subjects (twenty-two healthy volunteers and ten stroke patients) while they were in the supine position. It was measured in their bilateral upper and lower extremities. [Results] BaPWV was significantly increased in the stroke group compared with the healthy volunteers. It was also significantly increased on both the affected and non-affected sides of stroke patients in the stroke group. Furthermore, analysis of the pressure waveforms showed that the peak pressure was significantly increased in the stroke group compared with the control group. The peak pressure on both the affected and non-affected sides was also significantly greater than in the control group. However, the rise and decay times were significantly decreased in the stroke group compared with the control group. The rise and decay time on both the affected and non-affected sides were also significantly more decreased than in the control group. [Conclusion] The results demonstrated that increased BaPWV and changed pulse waves are closely associated with the pathologic states of hemiplegic stroke patients.