TENS to the posterior aspect of the legs decreases postural sway during stance

Effects of Combination of Functional Electric Stimulation and Robotic Leg Movement Using Dynamic Tilt Table on Walking Characteristics in Post-Stroke Patients with Spastic Hemiplegia: A Randomized Crossover-Controlled Trial

BACKGROUND

Spastic hemiplegia causes slow and unstable walking in post-stroke patients. Dynamic tilt table with robotic leg movement (DTTRLM) is safe and effective in improving walking. Functional electric stimulation (FES) improves walking speed in post-stroke patients with spastic hemiplegia. The aim of this study was to determine the effects of combined DTTRLM + FES on walking speed compared with DTTRLM alone.

METHODS

Twenty post-stroke patients were randomly assigned to receive either a single session of stepping + FES treatment or a single session of stepping alone treatment. After a one-week washout period, the same two groups underwent a single session of the other treatment, and the same measurements were taken. We measured walking speed, cadence, and the number of steps in a 10 m walking test (10MWT) and assessed Modified Ashworth Scale (MAS), Fugl-Meyer Assessment (FMA), and range of motion (ROM) before and after the intervention.

RESULTS

Stepping + FES significantly improved walking speed, number of steps, and ankle inversion ROM, compared with stepping alone. Adverse events were not observed in any subject.

CONCLUSIONS

Robotic stepping therapy combined with FES significantly improved 10 m walking speed (10MWS) compared with stepping only in patients with post-stroke and spastic hemiplegia. Further studies are needed to determine the long-term effects of the combination treatment.

The optimal exploitation of sensory electrical stimulation for regulating postural balance depends on participants' intrinsic balance abilities

BACKGROUND

The sensory electrical stimulation applied to the postural muscles provides additional sensory information that improves postural balance but this improvement seems to be highly subject-dependent.

RESEARCH QUESTION

The first aim was to analyse the effects of sensory electrical stimulation on postural balance and the second aim was to analyse these effects depending on intrinsic postural balance abilities of subjects.

METHODS

Twenty healthy young male participants completed a monopedal postural task with sensory electrical stimulation (1 ms; 10 Hz; 7 ± 2 mA i.e., twice the intensity corresponding to the sensory threshold) and without sensory electrical stimulation. Pearson's product-moment correlations were performed on centre of pressure parameters to assess whether the participant's balance abilities at baseline were related to the beneficial effects of sensory electrical stimulation.

RESULTS

The results showed positive correlations for all the variables measured (i.e., with r² from 0.32 to 0.35). Evidence suggests that subjects' abilities to take advantage from electrically induced additional afferents depended on participants' intrinsic balance abilities. In fact, subjects who exhibited the worst postural balance at baseline (i.e. without stimulation) benefited more from the effects of sensory electrical stimulation than subjects who displayed the best postural balance at baseline.

SIGNIFICANCE

In physically impaired subjects, as part of functional rehabilitation, sensory electrical stimulation would be particularly interesting in order to limit their risk of falling.

Sensory electrical stimulation and postural balance: a comprehensive review

PURPOSE

Sensory electrical stimulation (SES)-i.e., low-intensity electrical currents below, at, or just above the sensory threshold but below the motor threshold-is mainly used to restore/improve postural balance in pathological and healthy subjects. However, the ins and outs of its application as well as the neurophysiological effects induced are not yet well known. Hence, the aim of this paper was to address the effects of SES on postural balance based on these considerations.

METHOD

The immediate/concurrent effects (SES applied during postural balance measurements), the acute effects (SES durably applied before measuring postural balance) and the chronic effects (SES included in training/rehabilitation programs, i.e., measurements performed before and after the programs) were analysed with a comprehensive review.

RESULT

SES can lead to the improvement of postural balance using any of the three applications (immediate/concurrent, acute and chronic), notably in pathological subjects. The beneficial effects of SES can take place at the peripheral (sensory receptors sensitivity), spinal (spinal motoneural excitablity) and supra-spinal (cortex reorganisation or adaptation) levels. In healthy subjects, SES appears interesting, but too few studies have been conducted with this population to report clear results. Moreover, the literature is relatively devoid of comparative studies about the characteristics of the stimulation current (e.g., location, current parameters, duration).

CONCLUSION

In practice, SES appears to be particularly useful to reinforce or restore the postural function in the immediate/concurrent, acute or chronic application in pathlogical populations while its effects should be confirmed in healthy sujects by future studies. Moreover, future research should focus on the different characteristics of stimulation.

Effect of the application of somatosensory and excitomotor electrical stimulation during quiet upright standing balance

Somatosensory (which activates sensory neurons only) and excitomotor (which activates both motoneurons and sensory neurons) electrical stimulations applied on the musculature of the lower-limb are likely to facilitate and disturb balance control respectively. The aim of this study was to compare the possible balance control modifications induced by somatosensory (SS) and excitomotor (EX) electrical stimulations applied on the quadriceps femoris in quiet standing condition. Kinetics and kinematics parameters were recorded with a force platform (displacements of center of foot pressure) and a 3D analysis system (hip, knee and ankle angles) respectively during a postural task. Twenty healthy young male participants carried out a monopedal postural task (i.e., unilateral stance) in three conditions: SS stimulation (1ms; 10Hz; 7±2 mA i.e., twice the intensity corresponding to the sensory threshold), EX stimulation (400 µs; 50 Hz; 20 ± 5 mA i.e., twice the intensity corresponding to the motor threshold), and a control (CONT) condition without stimulation. The results showed no significant differences between the three conditions except for the knee' angle which was higher in the EX condition (167.3±11.6 vs 164.3±5.8 and 163.9±8) (p < 0.005) than in the two other conditions (SS stimulation and CONT). This means that the EX stimulation induced a postural position change (i.e., a slight knee extension) during the monopedal postural task without altering balance control. Overall, on the basis of the stimulation parameters used in the present work, neither the SS stimulation, nor the EX stimulation facilitated or disturbed postural balance.

Sensory Sub- and Suprathreshold TENS Exhibit No Immediate Effect on Postural Steadiness in Older Adults with No Balance Impairments

Transcutaneous electrical nerve stimulation (TENS) has been reported to attenuate postural sway; however, the results are inconclusive, with some indicating the effect and others not. The study aimed to evaluate the effect of sensory sub- and suprathreshold low-frequency TENS applied through the plantar surface and posterior aspect of shanks on postural sway. In a group of healthy community-dwelling older adults, TENS was delivered with two different current intensities: (1) subsensory which is below conscious perception and (2) suprasensory threshold which is within the range of conscious perception. Frequencies of the TENS stimulation were sweeping from 5 to 180 Hz and were delivered through the plantar surface and posterior shanks of both legs. Postural sway was measured with a force platform in eyes-open and eyes-closed conditions. To evaluate potential fast adaptability to TENS stimuli, the results were evaluated in two time intervals: 30 seconds and 60 seconds. The results indicated that TENS with the chosen frequencies and electrode placement did not affect postural sway in both the sub- and suprathreshold intensities of TENS, in eyes-open and eyes-closed conditions, and in 30-second and 60-second time intervals. In conclusion, given that in this study sub- and suprathreshold TENS applied via the plantar surface of the feet did not attenuate postural sway, it would be easy to conclude that this type of electrical stimuli is ineffective and no further research is required. We must caution against this, given the specificity of the electrode placements. We recommend that future research be performed consisting of individuals with balance impairments and with different positions of electrodes.

Multi-Sensorimotor Training Improves Proprioception and Balance in Subacute Stroke Patients: A Randomized Controlled Pilot Trial

Introduction: The objective was to determine whether advanced rehabilitation therapy combined with conventional rehabilitation therapy consisting of sensorimotor exercises would be superior to usual treadmill training for proprioception variation and balance ability in subacute stroke patients.

Methods: Thirty subjects (post-stroke time period: 3.96 ± 1.19 months) were randomly assigned to either a multi-sensorimotor training group (n = 19) or a treadmill training group (n = 18). Both groups first performed conventional physical therapy for 30 min, after which the multi-sensorimotor training group performed multi-sensorimotor training for 30 min, and the treadmill training group performed treadmill gait training for 30 min. Both groups performed the therapeutic interventions 5 days per week for 8 weeks. The primary outcome (proprioception variation) was evaluated using an acryl panel and electrogoniometer. The secondary outcome (balance ability) was measured using the Biodex Balance system before intervention and after 8 weeks.

Results: The multi-sensorimotor training and treadmill training groups showed significant improvement in proprioception variation and balance (overall, A-P and M-L) (all P < 0.05). In particular, the multi-sensorimotor training group showed more significant differences in proprioception variation (P = 0.002) and anterior-posterior (A-P) balance ability (P = 0.033) than the treadmill training group.

Conclusions: The multi-sensorimotor training program performed on multiple types of sensory input had a beneficial effect on proprioception sense in the paretic lower limb and A-P balance. A large-scale randomized controlled study is needed to prove the effect of this training.

Clinical Trial Registration:https://cris.nih.go.kr/cris/, identifier KCT0003097.

Dose postural control improve following application of transcutaneous electrical nerve stimulation in diabetic peripheral neuropathic patients? A randomized placebo control trial

BACKGROUND

peripheral neuropathy is the most common problem of diabetes. Neuropathy leads to lower extremity somatosensory deficits and postural instability in these patients. However, there are not sufficient evidences for improving postural control in these patients.

AIM

To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with diabetic neuropathy.

METHODS

Twenty eighth patients with diabetic neuropathy (40-55 Y/O) participated in this RCT study. Fourteen patients in case group received TENS and sham TENS was used for control group. Force plate platform was used to extract sway velocity and COP displacement parameters for postural control evaluation.

RESULTS

The mean sway velocity and center of pressure displacement along the mediolateral and anteroposterior axes were not significantly different between two groups after TENS application (p>0.05).

CONCLUSION

Application of 5min high frequency TENS on the knee joint could not improve postural control in patients with diabetic neuropathy.

Effects of different lower-limb sensory stimulation strategies on postural regulation-A systematic review and meta-analysis

Systematic reviews of balance control have tended to only focus on the effects of single lower-limb stimulation strategies, and a current limitation is the lack of comparison between different relevant stimulation strategies. The aim of this systematic review and meta-analysis was to examine evidence of effects of different lower-limb sensory stimulation strategies on postural regulation and stability. Moderate- to high- pooled effect sizes (Unbiased (Hedges’ g) standardized mean differences (SMD) = 0.31–0.66) were observed with the addition of noise in a Stochastic Resonance Stimulation Strategy (SRSS), in three populations (i.e., healthy young adults, older adults, and individuals with lower-limb injuries), and under different task constraints (i.e., unipedal, bipedal, and eyes open). A Textured Material Stimulation Strategy (TMSS) enhanced postural control in the most challenging condition—eyes-closed on a stable surface (SMD = 0.61), and in older adults (SMD = 0.30). The Wearable Garments Stimulation Strategy (WGSS) showed no or adverse effects (SMD = -0.68–0.05) under all task constraints and in all populations, except in individuals with lower-limb injuries (SMD = 0.20). Results of our systematic review and meta-analysis revealed that future research could consider combining two or more stimulation strategies in intervention treatments for postural regulation and balance problems, depending on individual needs.

The Effect of Mechanical Vibration Stimulation of Perception Subthreshold on the Muscle Force and Muscle Reaction Time of Lower Leg

The objective of this study is to investigate the effect of mechanical vibration stimulation on the muscle force and muscle reaction time of lower leg according to perception threshold and vibration frequency. A vibration stimulation with perception threshold intensity was applied on the Achilles tendon and tibialis anterior tendon. EMG measurement and analysis system were used to analyze the change of muscle force and muscle reaction time according to perception threshold and vibration frequency. A root-mean-square (RMS) value was extracted using analysis software and Maximum Voluntary Contraction (MVC) and Premotor Time (PMT) were analyzed. The measurement results showed that perception threshold was different from application sites of vibration frequency. Also, the muscle force and muscle reaction time showed difference according to the presence of vibration, frequency, and intensity. This result means that the vibration stimulation causes the change on the muscle force and muscle reaction time and affects the muscles of lower leg by the characteristics of vibration stimulation.

Can explicit visual feedback of postural sway efface the effects of sensory manipulations on mediolateral balance performance?

Explicit visual feedback on postural sway is often used in balance assessment and training. However, up-weighting of visual information may mask impairments of other sensory systems. We therefore aimed to determine whether the effects of somatosensory, vestibular, and proprioceptive manipulations on mediolateral balance are reduced by explicit visual feedback on mediolateral sway of the body center of mass and by the presence of visual information. We manipulated sensory inputs of the somatosensory system by transcutaneous electric nerve stimulation on the feet soles (TENS) of the vestibular system by galvanic vestibular stimulation (GVS) and of the proprioceptive system by muscle-tendon vibration (VMS) of hip abductors. The effects of these manipulations on mediolateral sway were compared with a control condition without manipulation under three visual conditions: explicit feedback of sway of the body center of mass (FB), eyes open (EO), and eyes closed (EC). Mediolateral sway was quantified as the sum of energies in the power spectrum and as the energy at the dominant frequencies in each of the manipulation signals. Repeated-measures ANOVAs were used to test effects of each of the sensory manipulations, of visual conditions and their interaction. Overall, sensory manipulations increased body sway compared with the control conditions. Absence of normal visual information had no effect on sway, while explicit feedback reduced sway. Furthermore, interactions of visual information and sensory manipulation were found at specific dominant frequencies for GVS and VMS, with explicit feedback reducing the effects of the manipulations but not effacing these.

The effects of exercise with TENS on spasticity, balance, and gait in patients with chronic stroke: a randomized controlled trial

Background

Transcutaneous electrical nerve stimulation (TENS) is a useful modality for pain control. TENS has recently been applied to decrease spasticity. The purpose of this study is to determine whether the addition of TENS to an exercise program reduces spasticity and improves balance and gait in chronic stroke patients.

Material/Methods

This was a single-blinded, multicenter, randomized controlled trial. Thirty-four ambulatory individuals with chronic stroke participated and were randomly allocated to the TENS or Placebo group. The TENS group performed therapeutic exercise with TENS while the placebo (non-stimulation) TENS group performed therapeutic exercise with placebo TENS. Participants in both groups followed the same 30-min exercise regimen 5 times per week for a period of 6 weeks. Spasticity (modified Ashworth scale), static (balance system), and dynamic balance (timed up and go test), and gait ability (gait analyzer) were measured at 1 week before and 1 week after the intervention.

Results

Significant differences were observed between the 2 groups. Spasticity improved by 0.80 points in the TENS group. Anterior-posterior and medial-lateral sway velocity among static balance parameters and dynamic balance showed significant differences between the TENS and Placebo TENS groups (p=.000). Gait speed and cadence were enhanced significantly in the TENS group (p=.000). Step and stride length on the paretic side showed a significant difference in the TENS group (p=.000), while only velocity showed a significant difference in the Placebo TENS group (p=.004).

Conclusions

A combination of therapeutic exercise and TENS may reduce spasticity and improve balance, gait, and functional activity in chronic stroke patients.

The effects of transcutaneous electrical nerve stimulation on joint position sense in patients with knee joint osteoarthritis

OBJECTIVE

To study the effects of transcutaneous electrical nerve stimulation (TENS) on joint position sense (JPS) in knee osteoarthritis (OA) subjects.

METHODS

Thirty subjects with knee OA (40-60 years old) using non-random sampling participated in this study. In order to evaluate the absolute error of repositioning of the knee joint, Qualysis Track Manager system was used and sensory electrical stimulation was applied through the TENS device.

RESULTS

The mean errors in repositioning of the joint, in two position of the knee joint with 20 and 60 degree angle, after applying the TENS was significantly decreased (p < 0.05).

CONCLUSION

Application of TENS in subjects with knee OA could improve JPS in these subjects.

A single trial of transcutaneous electrical nerve stimulation (TENS) improves spasticity and balance in patients with chronic stroke

Spasticity management is pivotal for achieving functional recovery of stroke patients. The purpose of this study was to investigate the effects of a single trial of transcutaneous electrical nerve stimulation (TENS) on spasticity and balance in chronic stroke patients. Forty-two chronic stroke patients were randomly allocated into the TENS (n = 22) or the placebo-TENS (n = 20) group. TENS stimulation was applied to the gastrocnemius for 60 min at 100 Hz, 200 µs with 2 to 3 times the sensory threshold (the minimal threshold in detecting electrical stimulation for subjects) after received physical therapy for 30 min. In the placebo-TENS group, electrodes were placed but no electrical stimulation was administered. For measuring spasticity, the resistance encountered during passive muscle stretching of ankle joint was assessed using the Modified Ashworth Scale, and the Hand held dynamometer was used to assess the resistive force caused by spasticity. Balance ability was measured using a force platform that measures postural sway generated by postural imbalance. The TENS group showed a significantly greater reduction in spasticity of the gastrocnemius, compared to the placebo-TENS group (p < 0.05). TENS resulted in greater balance ability improvements, especially during the eyes closed condition (p < 0.05). However, these effects returned to baseline values within one day. This study shows that TENS provides an immediately effective means of reducing spasticity and of improving balance in chronic stroke patients. The present data may be useful to establish the standard parameters for TENS application in the clinical setting of stroke.