Shmuel Springer

The correlation between postural control and upper limb position sense in people with chronic ankle instability

BackgroundChronic ankle instability (CAI) is attributed to functional instability driven by insufficient proprioception. However, it is not clear whether the deficits are related to global impaired performance or to specific decrease in ankle motor-control. The aim of this study was to assess the correlation between lower limb postural control and upper limb position sense among people with CAI, in order to further explore the function of the central neural control in people with CAI.MethodsFourteen participants (10 males, 4 females) with self-reported CAI and 14 age- and gender-matched, healthy controls participated in this study. Each participant completed single-limb stance postural control tests and shoulder position sense tests. The Overall Stability Index (OSI) was used as a measure of postural stability. The average of the absolute error score (AES) was calculated as a measure of shoulder position sense. Pearson correlations between the scores of the four body sites –lower limb postural stability (preferred/non-preferred), shoulder (preferred/non-preferred) were determined separately for each group.ResultsIn the control group, significant correlations were found between the OSI score of the right and left ankles (r = 0.887, p < 0.001), between the AES of the right and left shoulders (r = 0.656, p = 0.011), as well as between the OSI score and the AES of the non-preferred side (r = 0.649, p = 0.012). In the CAI group, significant correlation was found only between the OSI score at both ankles (r = 0.6, p = 0.002).ConclusionsIndividuals with CAI demonstrated lower limb postural control and upper limb position sense similar to those shown in healthy controls. However, correlations between the lower and upper limbs were observed only in the healthy controls. Clinicians can use this information and employ activities that focus on coordinating the upper and lower extremities when designing neuromuscular control training programs for people with CAI.

The effect of electrode placement and interphase interval on force production during stimulation of the dorsiflexor muscles.

The aims of this study were to investigate whether introducing an interphase interval (IPI) to biphasic pulses during stimulation of the dorsiflexor muscles would affect force production and to determine whether the IPI effect is dependent on electrode position. Twelve healthy volunteers participated in the study. Each subject participated in one session during which electrically induced contraction (EIC) forces of the ankle dorsiflexors were measured with five different IPI settings ranging from 0 to 400 μs. Forces of EICs were assessed with the electrodes placed either with the proximal electrode positioned over the common peroneal nerve and the second electrode over the dorsiflexor muscles or with both electrodes located over the dorsiflexor muscles. The order of electrode placements and of the different IPI settings was randomized across subjects. The results indicated that the introduction of a 100-μs-long IPI may enhance force production when one electrode is located over the common peroneal nerve. However, increasing the duration of the IPI beyond 100 μs did not result in further increase in force production. In contrast, the introduction of an IPI did not increase force production when both electrodes were located over the dorsiflexor muscles. These findings may help to optimize stimulation settings during functional electrical stimulation to prevent foot-drop.

Clinical decision making for using electro-physical agents by physiotherapists, an Israeli survey

BackgroundElectro-physical agents (EPAs) are fundamental components in the management arsenal of physiotherapy. The objective of this study was to provide a comprehensive understanding of the factors affecting the decisions made by Physiotherapists (PTs) when choosing to apply EPAs as a treatment modality.MethodsA purpose-designed questionnaire was developed to investigate the contribution of 13 factors on the decision to use EPAs. Two hundred questionnaires were randomly distributed to PTs attending the annual conference of the Israeli Physiotherapy Society, 2014. The factors were grouped into six categories and Wilcoxon Sign Rank tests were applied to compare their impact on decision making.ResultsIn total, 144 (72%) questionnaires were completed. Good internal consistency was found for the 13 component of the decisions factors (Cronbach’s coefficient alpha = 0.77) with unequal distribution of answers in each question (p < 0.01).Eighty-one percent of the participants reported past experience, and 55 % mentioned research evidence as strong or very strong factors which influence their decision to use of EPAs. However, only 38% of the participants reported patients’ preferences as a strong or very strong factor. Comparisons between the six categories of the decision factors determined three levels of impact (rank scores) which were significantly different from each other (p < 0.01). Availability of equipment ranked the highest. The lowest level of impact included two categories, technology related issues and patients’ and physicians’ preferences.ConclusionThe participating PTs were likely to make decisions which were strongly impacted by availability of equipment and operational factors. This research can be used to provide practicing PTs with a basis for a critical appraisal of their decision making regarding the application of EAPs. In addition, due to the strong impact of availability of equipment, health policy makers should verify that the available equipment is up to date with the best research evidence.

The Effect of an Interphase Interval on Electrically Induced Dorsiflexion Force and Fatigue in Subjects With an Upper Motor Neuron Lesion

The study objective was to investigate the effects of an interphase interval (IPI) interposed between the two phases of a biphasic symmetric pulse, on electrically induced contraction (EIC) forces and fatigue during stimulation of the ankle dorsiflexors in individuals with an upper motor neuron lesion (UMNL). The dorsiflexor muscles of 20 subjects with UMNL routinely using functional electrical stimulation to correct a foot drop during ambulation, were electrically stimulated with biphasic pulses (250 µs phase duration and 35 Hz pulse frequency) using nine IPI durations (ranging from 0 to 400 µs). The induced muscle force and fatigue were measured. A significant positive correlation was found between IPI duration and induced muscle force. Introducing a 250 µs IPI significantly decreased rate of muscle fatigue compared to stimulation with no IPI (P < 0.05). Thus, the introduction of an IPI may reduce the current intensity required to achieve a specific force during functional electrical stimulation in individuals with UMNL. Reduction in muscle fatigue may shorten the conditioning period necessary for first time users of functional electrical stimulation.

Effects of interphase interval and stimulation form on dorsiflexors contraction force.

BACKGROUND Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation to restore movement to patients following orthopedic and neurological injuries. When applying NMES the goal is to induce the strongest contractions with minimal discomfort. OBJECTIVE This study aimed to determine whether introducing an interphase interval (IPI) to 400 μ sec biphasic pulses during stimulation of the dorsiflexor muscles would have the same effect on force production and stimulation discomfort when stimulation was controlled by constant current (CC) or constant voltage (CV). METHODS Eighteen healthy volunteers participated in the study. Each subject participated in one session. Electrically induced contraction (EIC) forces and degree of discomfort were measured during stimulation of the ankle dorsiflexors with 0, 100 and 200 μ sec IPI settings with CC or CV. RESULTS Compared to IPI = 0 μ sec, introduction of a 200 μ sec IPI increased force production with CC stimulation without increasing discomfort. No other enhancements in the EIC force compared to IPI = 0 μ sec were found between the IPIs with CC or CV. CONCLUSIONS IPI may increase the effectiveness of biphasic pulse with CC, but not with CV stimulation.

Effects of functional electrical stimulation on gait in people with multiple sclerosis – A systematic review

BACKGROUND Functional electrical stimulation (FES) is commonly used to ameliorate gait deficits in patients with multiple sclerosis (PwMS). This review critically evaluates the literature describing the orthotic and therapeutic effects of FES on gait in PwMS. METHODS The PubMed, CINAHL, and ProQuest databases were searched. Included were studies that evaluated therapeutic and/or orthotic effects of FES in PwMS with at least one outcome measure related to gait. Methodology was assessed using the Downs and Black checklist. RESULTS Twelve relevant studies were reviewed. Their methodological quality ranged from 14 to 21 of 28. Eleven studies reported the effects of peroneal stimulation. Most found a significant orthotic effect (measured during stimulation), mainly on walking speed. Only three assessed the therapeutic effect (carry-over), which was not significant. CONCLUSIONS The evidence presented in this review suggests that FES has a positive orthotic effect on walking in PwMS. Yet, more robust trials are needed to substantiate this finding. Therapeutic efficacy of FES was not demonstrated, and almost all studies tested a single channel peroneal stimulator. Future studies involving FES technological innovations with advanced clinical approaches might contribute to a carry-over effect from FES and increase the percentage of PwMS who benefit from this technology.

Spatiotemporal Gait Parameters as Predictors of Lower-Limb Overuse Injuries in Military Training

The study objective was to determine whether spatiotemporal gait parameters could predict lower-limb overuse injuries in cohort of combat soldiers during first year of military service. Newly recruited infantry soldiers walked on a treadmill at a 15° incline with a fixed speed of 1.67 m/sec while wearing a standard military vest with a 10 kg load. Stride time variability, stride length variability, step length asymmetry, and the duration of the loading response phase of the gait cycle were measured. Injury data on 76 soldiers who did not report musculoskeletal complaints at initial screening were collected one year after recruitment. Multiple logistic regression analyses were conducted to determine the predictive effect of the gait parameters on lower-limb injuries. Twenty-four soldiers (31.6%) had overuse injuries during the first year after recruitment. Duration of the loading response was a significant predictor of general lower-limb injury (p < 0.05), as well as of foot/ankle and knee injuries (p < 0.05, p < 0.01, resp.). A cutoff value of less than 12.15% for loading response duration predicted knee injuries with 83% sensitivity and 67% specificity. This study demonstrates the utility of spatiotemporal gait evaluation, a simple screening tool before military training, which may help to identify individuals at risk of lower-limb overuse injuries.

Ulnar Nerve Conduction Block Using Surface Kilohertz Frequency Alternating Current: A Feasibility Study: Thoughts and Progress

The aim of this study was to test the effects of kilohertz frequency alternating current (KHFAC) surface stimulation applied to the ulnar nerve on force and myoelectrical activity of the abductor digiti minimi (ADM) muscle. Eighteen healthy volunteers (age: 27.6 ± 7.9 years; 10 males, 8 females) were included in the study. Each subject participated in one session during which a biphasic 7 kHz rectangular pulse was delivered above the medial epicondyle of the humerus to induce ulnar nerve blocking. ADM electromyographic (EMG) activity and contraction force were measured before (Pre), immediately after, and following 5 and 10 min post stimulation (post 1, post 2). The results showed that EMG activity decreased immediately after stimulation compared to prestimulation, it returned to the level of prestimulation at 5 min (post 1), and decreased again at 10 min (post 2). Furthermore, analysis of compound adjusted z-score indicated significant decrease of force and myoelectrical activity immediately, and 10 min post stimulation. The findings, which demonstrate that KHFAC surface stimulation of the ulnar nerve may decrease the motor activity of intrinsic hand muscle, can help to develop future methods of neuromodulation to treat hand spasticity.

Transcutaneous neuromuscular electrical stimulation may be beneficial in the treatment of premature ejaculation

Approximately 20-30% of sexually active men suffer from Premature Ejaculation (PE), but the pathophysiology still remains unclear and the current available treatments for PE are unsatisfying. Considering the role of rhythmic bulbospongiosus and ischiocavernosus Muscles contractions on the ejaculatory reflex, we hypothesize that weakening this muscles via inhibiting its contractions by Application of Neuromuscular Electrical Stimulation prior to the planned sexual activity, may have a beneficial effect in the treatment of PE. Using miniaturized perineal on-demand stimulation device, in a home setting during sexual intercourse may become the first line of treatment for PE.

Knee position sense: does the time interval at the target angle affect position accuracy?

[Purpose] This study examined whether the interval at the target angle during knee joint position sense (JPS) affected reposition accuracy, and evaluated the consequence of this factor on test-retest reliability. [Subjects and Methods] Twenty healthy subjects participated in this study. Reposition ability was measured after the knee was placed at a target angle (ranging from 40° to 60°) for intervals of 3, 6, 9, and 12 seconds, in randomized order. Two trials were performed for each condition. The measurement was repeated after a week. The absolute error (AE) of each trial and average AE under each condition within the two measures were used for data analysis. [Results] No significant difference was found in comparing the AE or the average AE during all trials and between the two measures. Fair-to-good reliability was found for the AE results of all trials under the conditions of 3, 6, and 12 seconds. Poor reliability was found with time interval of 9 seconds. [Conclusion] The length of time needed to memorize the target angle during knee JPS test might affect test reliability. Practitioners can use this information when collecting JPS data.