Role of ß-Alanine Supplementation on Cognitive Function, Mood, and Physical Function in Older Adults; Double-Blind Randomized Controlled Study.

This study investigated 10 weeks of ß-alanine (BA) supplementation on changes in cognitive function, mood, and physical performance in 100 older adults (70.6 ± 8.7 y). Participants were randomized into a BA (2.4 g·d-1) or placebo (PL) group. Testing occurred prior to supplementation (PRE), at the midpoint (MID), and at week-10 (POST). Participants completed cognitive function assessments, including the Montreal cognitive assessment (MOCA) and the Stroop pattern recognition test, at each testing session. Behavioral questionnaires [i.e., the profile of mood states, geriatric depression scale (GDS), and geriatric anxiety scale (GAS)] and physical function assessments (grip strength and timed sit-to-stand) were also conducted. No difference between groups was noted in MoCA scores (p = 0.19). However, when examining participants whose MOCA scores at PRE were at or below normal (i.e., ≤26), participants in BA experienced significant improvements in MOCA scores at MID (13.6%, p = 0.009) and POST (11.8%, p = 0.016), compared to PL. No differences were noted in mood scores, GAS, or any of the physical performance measures. A significant decrease was observed in the GDS for participants consuming BA but not in PL. Results suggested that BA supplementation can improve cognitive function in older adults whose cognitive function at baseline was at or below normal and possibly reduce depression scores.

Transcutaneous functional electrical stimulation-a novel therapy for premature ejaculation: results of a proof of concept study.

Premature Ejaculation (PE) is a very common and disturbing sexual dysfunction in men. Currently available treatment modalities are associated with limited efficacy and low treatment adherence. In this prospective, single-blinded, self-controlled study, we evaluated the efficacy and safety of transcutaneous electrical stimulation (TES) for the treatment of (PE). We included 23 patients aged 20-60 (mean: 38.7) with lifelong PE. On the first visit, we delivered either TES or sham treatment to the perineum, based on the enrollment order. For stimulation, we used a commercial neuromuscular electrical stimulation device. The patients were invited for the second visit after at least 7 days for receiving the alternating treatment. During the treatment sessions, the patients were left alone in a privet silent room to masturbate and a stopwatch was used to measure their masturbation ejaculatory latency time (MELT). The patients also filled-out safety questionnaires after each visit and on each of the 3 following days. Of the 20 patients who completed the study, 17 (85%) experienced prolonged MELT under TES compared with the sham treatment. Mean MELT values increased 3.5-folds under TES (p = 0.0009). We demonstrated a significant increase in MELT in lifelong PE patients using TES. This therapeutic option may have the potential to become an on-demand treatment option for PE. Future studies with wireless devices are needed to confirm the efficacy and safety of this treatment concept during intercourse.

Functional electrical stimulation following anterior cruciate ligament reconstruction: a randomized controlled pilot study.

BACKGROUND: Inadequate quadriceps strength following anterior cruciate ligament reconstruction (ACLR) often results in alterations in gait pattern that are usually reported during loading response. Neuro-muscular electrical stimulation (NMES) is frequently used to overcome this quadriceps weakness. Despite the beneficial effects of NMES, persistent deficits in strength and gait are reported. The aim of this study was to investigate the feasibility of applying quadriceps functional electrical stimulation (FES) during walking in addition to standard rehabilitation, in the initial stage of ACLR rehabilitation. METHODS: Subjects were randomized to quadriceps FES synchronized with walking group (n = 10) or quadriceps NMES (duty cycle of 10 s on/10 s off) group (n = 13). Both interventions were performed for 10 min three days a week, in addition to a standard rehabilitation program. Assessments were performed up to 2 weeks before the ACLR (pre-ACLR), and 4 weeks postoperatively. Outcomes measured were gait speed, single limb stance gait symmetry, quadriceps isometric peak strength ratio (peak strength at 4 weeks/peak strength pre-ACLR) and peak strength inter-limb symmetry. Gait outcomes were also assessed 1-week post-surgery. RESULTS: Subjects in both groups regained pre-ACLR gait speed and symmetry after 4 weeks of rehabilitation, with no difference between groups. However, although pre-ACLR quadriceps peak strength was similar between groups (FES - 205 Nm, NMES - 225 Nm, p = 0.605), subjects in the FES group regained 82% of their pre-quadriceps strength compared to 47% in the NMES group (p = 0.02). In addition, after 4 weeks, the FES group had significantly better inter-limb strength symmetry 0.63 ± 0.15 vs. 0.39 ± 0.18 in the NMES group (p = 0.01). CONCLUSIONS: Quadriceps FES combined with traditional rehabilitation is a feasible, early intervention treatment option, post-ACLR. Furthermore, at 4 weeks post-surgery, FES was more effective in recovering quadriceps muscle strength than was NMES. While spatiotemporal gait parameters did not differ between groups, kinetic and kinematic studies may be useful to further understand the effects of quadriceps FES post-ACLR. The promising results of this preliminary investigation suggest that such studies are warranted. TRIAL REGISTRATION: ISRCTN 02817399 . First posted June 29, 2016.

Ulnar Nerve Conduction Block Using Surface Kilohertz Frequency Alternating Current: A Feasibility Study.

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.

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.

Effects of amplitude and phase-duration modification on electrically induced contraction force and discomfort.

BACKGROUND: Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation. However, the optimal combination of phase-duration and amplitude for enhancing motor output is not yet resolved. OBJECTIVE: To test the effects of increasing phase-duration and amplitude on isometric knee extension force and discomfort, while controlling the effects of electrode-skin resistance and body mass index (BMI). METHODS: Twenty-one healthy volunteers participated in the study. Stimulation was set at 250 µsec phase-duration and 45 Hz to evoke 10% of maximal voluntary isometric contraction of the quadriceps. Electrode-skin resistance was measured. Then, electrically induced contraction (EIC) forces and discomfort level were measured under four conditions: Moderate (25%) or substantial increase (50%) from baseline amplitude with constant phase-duration and moderate (25%) or substantial increase (50%) in phase-duration with amplitude constant. RESULTS: Compared with baseline, EIC force was significantly higher in all intensification conditions, while discomfort was significantly greater in all conditions except for moderate increase in phase-duration (p= 0.44). Amplitude intensification produced significantly higher force and greater discomfort than phase-duration. Electrode-skin resistance and BMI were not significant covariates. CONCLUSIONS: Greater force is elicited by increasing amplitude than by similar increase in phase-duration; however, the associated discomfort is also higher. Clinicians may use phase-duration while conditioning for NMES.

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.

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.

Dual-channel functional electrical stimulation improvements in speed-based gait classifications.

BACKGROUND: Functional electrical stimulation (FES) is becoming an accepted treatment method for enhancing gait performance in patients who present with gait difficulties resulting from hemiparesis. The purpose of this study was to test whether individuals with hemiparesis who have varied gait speeds, which place them in different functional categories, benefit to the same extent from the application of FES. METHODS: Thirty-six subjects with chronic hemiparesis demonstrating foot-drop and deficits in knee and/or hip control were fitted with a dual-channel FES system activating the dorsiflexors and hamstring muscles. Gait was assessed during a 2-minute walk test with and without stimulation. A second assessment was conducted after 6 weeks of daily use. Analysis was performed with the subjects stratified into three functional ambulation classes according to their initial gait categories. RESULTS: The dual-channel FES improved the gait velocity of all three subgroups. No minimal gait velocity was required in order to gain benefits from FES. For example, subjects with limited household ambulation capabilities improved their gait speed by 63.3% (from 0.30 ± 0.09 m/sec to 0.49 ± 0.20 m/sec; P < 0.01), while subjects with functional community ambulation capabilities improved their gait speed by 25.5% (from 0.90 ± 0.11 m/sec to 1.13 ± 0.22 m/sec; P < 0.01). CONCLUSION: Dual-channel FES positively affects gait velocity in patients with chronic hemiparesis, regardless of their initial gait velocity. Furthermore, gait velocity gains may be large enough to change an individual's ambulation status to a higher functional category.

The effects of dual-channel functional electrical stimulation on stance phase sagittal kinematics in patients with hemiparesis.

Sixteen subjects (aged 54.2 ± 14.1 years) with hemiparesis (7.9 ± 7.1 years since diagnosis) demonstrating a foot-drop and hamstrings muscle weakness were fitted with a dual-channel functional electrical stimulation (FES) system activating the dorsiflexors and hamstrings muscles. Measurements of gait performance were collected after a conditioning period of 6 weeks, during which the subjects used the system throughout the day. Gait was assessed with and without the dual-channel FES system, as well as with peroneal stimulation alone. Outcomes included lower limb kinematics and the step length taken with the non-paretic leg. Results with the dual-channel FES indicate that in the subgroup of subjects who demonstrated reduced hip extension but no knee hyperextension (n = 9), hamstrings FES increased hip extension during terminal stance without affecting the knee. Similarly, in the subgroup of subjects who demonstrated knee hyperextension but no limitation in hip extension (n = 7), FES restrained knee hyperextension without having an impact on hip movement. Additionally, step length was increased in all subjects. The peroneal FES had a positive effect only on the ankle. The results suggest that dual-channel FES for the dorsiflexors and hamstrings muscles may affect lower limb control beyond that which can be attributed to peroneal stimulation alone.

Effects of dual-channel functional electrical stimulation on gait performance in patients with hemiparesis.

The study objective was to assess the effect of functional electrical stimulation (FES) applied to the peroneal nerve and thigh muscles on gait performance in subjects with hemiparesis. Participants were 45 subjects (age 57.8 ± 14.8 years) with hemiparesis (5.37 ± 5.43 years since diagnosis) demonstrating a foot-drop and impaired knee control. Thigh stimulation was applied either to the quadriceps or hamstrings muscles, depending on the dysfunction most affecting gait. Gait was assessed during a two-minute walk test with/without stimulation and with peroneal stimulation alone. A second assessment was conducted after six weeks of daily use. The addition of thigh muscles stimulation to peroneal stimulation significantly enhanced gait velocity measures at the initial and second evaluation. Gait symmetry was enhanced by the dual-channel stimulation only at the initial evaluation, and single-limb stance percentage only at the second assessment. For example, after six weeks, the two-minute gait speed with peroneal stimulation and with the dual channel was 0.66 ± 0.30 m/sec and 0.70 ± 0.31 m/sec, respectively (P < 0.0001). In conclusion, dual-channel FES may enhance gait performance in subjects with hemiparesis more than peroneal FES alone.