Explore the vast range of titles available.

Recently commercialized powered prosthetic arm systems hold great potential in restoring function for people with upper-limb loss. However, effective use of such devices remains limited by conventional (direct) control methods, which rely on electromyographic signals produced from a limited set of muscles. Targeted Muscle Reinnervation (TMR) is a nerve transfer procedure that creates additional recording sites for myoelectric prosthesis control. The effects of TMR may be enhanced when paired with pattern recognition technology. We sought to compare pattern recognition and direct control in eight transhumeral amputees who had TMR in a balanced randomized cross-over study. Subjects performed a 6–8 week home trial using direct and pattern recognition control with a custom prostheses made from commercially available parts. Subjects showed statistically better performance in the Southampton Hand Assessment Procedure (p = 0.04) and the Clothespin relocation task (p = 0.02). Notably, these tests required movements along 3 degrees of freedom. Seven of 8 subjects preferred pattern recognition control over direct control. This study was the first home trial large enough to establish clinical and statistical significance in comparing pattern recognition with direct control. Results demonstrate that pattern recognition is a viable option and has functional advantages over direct control.

Purpose The objective was to examine the impact of non-postural muscle fatigue on anticipatory postural control, during postural perturbations induced by platform translations. The experimental setup investigated the central changes caused by fatigue without the potential confounding influence of peripheral fatigue within the postural muscles. Methods Fatigue induced in forearm muscles by a maximal handgrip contraction has been previously shown to influence forearm force production for 10 min, reduce ankle plantarflexion force for 1 min and create measureable central fatigue for 30 s. The peak-to-peak anterior/posterior displacement of the center of mass and center of pressure (COP) and muscle activity were measured during the postural perturbation tasks performed before the fatigue protocol and for 10 min post-fatigue. Results The fatigue protocol decreased the peak-to-peak COP displacement from 128.0 ± 12.3 mm pre-fatigue to 81.9 ± 7.8 mm post-fatigue during the forwards platform translation ( p  < 0.05) and from 133.8 ± 12.0 to 89.2 ± 7.9 mm during the backwards translation ( p  < 0.05). The fatigue protocol also caused the tibialis anterior (TA pre-fatigue = −0.25 ± 0.04 s, TA post-fatigue = −0.41 ± 0.02 s, p  = 0.001) and medial gastrocnemius muscles (MG pre-fatigue = −0.39 ± 0.03 s, MG post-fatigue = −0.48 ± 0.02 s, p  = 0.028) to be recruited significantly earlier relative to the pre-fatigue condition. Conclusion This experimental setup ensured that peripheral fatigue did not develop in the postural muscles; therefore, a general fatigued-induced modification of the postural strategy is proposed as the origin of the postural changes and delayed recovery.

PurposeCross-education reduces quadriceps weakness 8 weeks after anterior cruciate ligament (ACL) surgery, but the long-term effects are unknown. We investigated whether cross-education, as an adjuvant to the standard rehabilitation, would accelerate recovery of quadriceps strength and neuromuscular function up to 26 weeks post-surgery.MethodsGroup allocation was randomized. The experimental (n = 22) and control (n = 21) group received standard rehabilitation. In addition, the experimental group strength trained the quadriceps of the non-injured leg in weeks 1–12 post-surgery (i.e., cross-education). Primary and secondary outcomes were measured in both legs 29 ± 23 days prior to surgery and at 5, 12, and 26 weeks post-surgery.ResultsThe primary outcome showed time and cross-education effects. Maximal quadriceps strength in the reconstructed leg decreased 35% and 12% at, respectively, 5 and 12 weeks post-surgery and improved 11% at 26 weeks post-surgery, where strength of the non-injured leg showed a gradual increase post-surgery up to 14% (all p ≤ 0.015). Limb symmetry deteriorated 9–10% more for the experimental than control group at 5 and 12 weeks post-surgery (both p ≤ 0.030). One of 34 secondary outcomes revealed a cross-education effect: Voluntary quadriceps activation of the reconstructed leg was 6% reduced for the experimental vs. control group at 12 weeks post-surgery (p = 0.023). Both legs improved force control (22–34%) and dynamic balance (6–7%) at 26 weeks post-surgery (all p ≤ 0.043). Knee joint proprioception and static balance remained unchanged.ConclusionStandard rehabilitation improved maximal quadriceps strength, force control, and dynamic balance in both legs relative to pre-surgery but adding cross-education did not accelerate recovery following ACL reconstruction.

Purpose The use of a peripheral nerve stimulator to assess the level of neuromuscular blockade tasks the anesthesia clinician with subjectively assessing the response to neurostimulation. In contrast, objective neuromuscular monitors provide quantitative information. The purpose of this study was to compare subjective evaluations from a peripheral nerve stimulator with objective measurements of neurostimulation responses from a quantitative monitor. Methods Patients were enrolled preoperatively, and intraoperative neuromuscular blockade management was at the discretion of the anesthesiologist. Electromyography electrodes were placed over the dominant or nondominant arm in a randomized fashion. Following onset of nondepolarizing neuromuscular blockade, the ulnar nerve was stimulated, the response was measured with electromyography, and anesthesia clinicians, who were blinded to the objective measurements, subjectively (visually) evaluated the response to neurostimulation. Results Fifty patients were enrolled and 666 neurostimulations were performed at 333 different time points. Anesthesia clinicians subjectively overestimated the response of the adductor pollicis muscle following neurostimulation of the ulnar nerve 155/333 (47%) of the time when compared with objective electromyographic measurements. When subjective evaluations and objective measurements differed to any degree, subjective evaluations were higher than objective measurements 155/166 (92%) of the time (95% CI, 87 to 95; P < 0.001), representing significant evidence that subjective evaluation overestimates the response to train-of-four stimulation. Conclusions Subjective observations of a “twitch” do not consistently correspond to objective measurements of neuromuscular blockade with electromyography. Subjective evaluation overestimates the response to neurostimulation and may be unreliable for determining the depth of block or confirming adequate recovery.

A large proportion of spinal cord injuries (SCI) are incomplete. Even in clinically complete injuries, silent non-functional connections can be present. Therapeutic approaches that can strengthen transmission in weak neural connections to improve motor performance are needed. Our aim was to determine whether long-term delivery of paired associative stimulation (PAS, a combination of transcranial magnetic stimulation [TMS] with peripheral nerve stimulation [PNS]) can enhance motor output in the hands of patients with chronic traumatic tetraplegia, and to compare this technique with long-term PNS. Five patients (4 males; age 38–68, mean 48) with no contraindications to TMS received 4 weeks (16 sessions) of stimulation. PAS was given to one hand and PNS combined with sham TMS to the other hand. Patients were blinded to the treatment. Hands were selected randomly. The patients were evaluated by a physiotherapist blinded to the treatment. The follow-up period was 1 month. Patients were evaluated with Daniels and Worthingham's Muscle Testing (0–5 scale) before the first stimulation session, after the last stimulation session, and 1 month after the last stimulation session. One month after the last stimulation session, the improvement in the PAS-treated hand was 1.02 ± 0.17 points (p < 0.0001, n = 100 muscles from 5 patients). The improvement was significantly higher in PAS-treated than in PNS-treated hands (176 ± 29%, p = 0.046, n = 5 patients). Long-term PAS might be an effective tool for improving motor performance in incomplete chronic SCI patients. Further studies on PAS in larger patient cohorts, with longer stimulation duration and at earlier stages after the injury, are warranted.

IntroductionMaximal strength training (MST), performed with heavy loads (~ 90% of one repetition maximum; 1RM) and few repetitions, yields large improvements in efferent neural drive, skeletal muscle force production, and skeletal muscle efficiency. However, it is elusive whether neural adaptations following such high intensity strength training may be accompanied by alterations in energy-demanding muscular factors.MethodsSixteen healthy young males (24 ± 4 years) were randomized to MST 3 times per week for 8 weeks (n = 8), or a control group (CG; n = 8). Measurements included 1RM and rate of force development (RFD), and evoked potentials recordings (V-wave and H-reflex normalized to M-wave (M) in the soleus muscle) applied to assess efferent neural drive to maximally contracting skeletal muscle. Biopsies were obtained from vastus lateralis and analyzed by western blots and real-time PCR to investigate the relative protein expression and mRNA expression of Sarcoplasmic Reticulum Ca2+ ATPase (SERCA) 1 and SERCA2.ResultsSignificant improvements in 1RM (17 ± 9%; p < 0.001) and early (0–100 ms), late (0–200 ms) and maximal RFD (31–53%; p < 0.01) were observed after MST, accompanied by increased maximal Vmax/Msup-ratio (9 ± 14%; p = 0.046), with no change in H-reflex to M-wave ratio. No changes were observed in the CG. No pre- to post-training differences were found in mRNA or protein expressions of SERCA1 and SERCA2 in either group.ConclusionMST increased efferent neural drive to maximally contracting skeletal muscle, causing improved force production. No change was observed in SERCA expression, indicating that responses to high intensity strength training may predominantly be governed by neural adaptations.

Context: With regard to intermittent training exercise, the effects of the mode of recovery on subsequent performance are equivocal. Objective: To compare the effects of 3 types of recovery intervention on peak torque (PT) and electromyographic (EMG) activity of the knee extensor muscles after fatiguing isokinetic intermittent concentric exercise. Design: Crossover study. Setting: Research laboratory. Patients or Other Participants: Eight elite judo players (age = 18.4 ± 1.4 years, height = 180 ± 3 cm, mass = 77.0 ± 4.2 kg). Intervention(s): Participants completed 3 randomized sessions within 7 days. Each session consisted of 5 sets of 10 concentric knee extensions at 80% PT at 120°/s, with 3 minutes of recovery between sets. Recovery interventions were passive, active, and electromyostimulation. The PT and maximal EMG activity were recorded simultaneously while participants performed isokinetic dynamometer trials before and 3 minutes after the resistance exercise. Main Outcome Measure(s): The PT and maximal EMG activity from the knee extensors were quantified at isokinetic velocities of 60°/s, 120°/s, and 180°/s, with 5 repetitions at each velocity. Results: The reduction in PT observed after electromyo-stimulation was less than that seen after passive ( P < .001) or active recovery ( P < .001). The reduction in PT was less after passive recovery than after active recovery ( P < .001). The maximal EMG activity level observed after electromyostimulation was higher than that seen after active recovery ( P < .05). Conclusions: Electromyostimulation was an effective recovery tool in decreasing neuromuscular fatigue after high-intensity, intermittent isokinetic concentric exercise for the knee extensor muscles. Also, active recovery induced the greatest amount of neuromuscular fatigue.

This study investigated the effects of low- and high-volume strength trainings on neuromuscular adaptations of lower- and upper-body muscles in older women after 6 weeks (6WE), 13 weeks (13WE), and 20 weeks (20WE) of training. Healthy older women were assigned to low-volume (LV) or high-volume (HV) training groups. The LV group performed one set of each exercise, while the HV group performed three sets, 2 days/week. Knee extension and elbow flexion one-repetition maximum (1-RM), maximal isometric strength, maximal muscle activation, and muscle thickness (MT) of the lower- and upper-body muscles, as well as lower-body muscle quality (MQ) obtained by ultrasonography, were evaluated. Knee extension and elbow flexion 1-RM improved at all time points for both groups; however, knee extension 1-RM gains were greater for the HV group after 20WE. Maximal isometric strength of the lower body for both groups increased only at 20WE, while upper-body maximal isometric strength increased after 13WE and 20WE. Maximal activation of the lower and upper body for both groups increased only after 20WE. Both groups showed significant increases in MT of their lower and upper body, with greater gains in lower-body MT for the HV group at 20WE. MQ improved in both groups after 13WE and 20WE, whereas the HV group improved more than the LV group at 20WE. These results showed that low- and high-volume trainings have a similar adaptation time course in the muscular function of upper-body muscles. However, high-volume training appears to be more efficient for lower-body muscles after 20 weeks of training.

Objective Although neural adaptations from strength training are known to occur, the acute responses associated with heavy-strength (HST) and hypertrophy training (HYT) remain unclear. Therefore, we aimed to compare the acute behaviour of corticospinal responses following a single session of HST vs HYT over a 72-h period. Methods Fourteen participants completed a random counterbalanced, crossover study that consisted of a single HST session [5 sets × 3 repetition maximum (RM)], a HYT session (3 sets × 12 RM) of the leg extensors and a control session (CON). Single- and paired-pulse transcranial magnetic stimulation (TMS) was used to measure changes in motor-evoked potential (MEP) amplitude, corticospinal silent period (CSP), intra-cortical facilitation (ICF), short-interval intra-cortical inhibition (SICI) and long-interval intra-cortical inhibition (LICI). Additionally, maximal muscle compound wave ( M MAX ) of the rectus femoris (RF) and maximal voluntary isometric contraction (MVIC) of the leg extensors were taken. All measures were taken at baseline, immediately post and 2, 6, 24, 48 and 72 h post-training. Results A significant condition x time interaction was observed for MVIC ( P  = 0.001), M MAX ( P  = 0.003), MEP amplitude ( P  < 0.001) and CSP ( P  = 0.002). No differences were observed between HST and HYT for all neurophysiological measures. No changes in SICI, ICF and LICI were observed compared to baseline. Conclusion Our results suggest that: (1) the acute behaviour of neurophysiological measures is similar between HST and HYT; and (2) the increase in corticospinal excitability may be a compensatory response to attenuate peripheral fatigue.

Background The neurodynamic mobilization (NM) technique is an intervention designed to restore homeostasis by mobilizing the nervous system and its surrounding structures. NM, through its physiological and biomechanical mechanisms, may play a role in modulating delayed Onset Muscle Soreness (DOMS) symptoms and regulating the emerging inflammatory response. The aim of this study was to determine the preventive effects of the NM technique on DOMS. Methods Thirty-four untrained males were randomized into the NM ( n  = 17) or placebo NM ( n  = 17) group. Femoral nerve NM and placebo NM techniques were performed for three weeks in both groups. All the participants subsequently performed 300 maximal isokinetic eccentric contractions of the dominant knee extensors. Markers of muscle damage (creatine kinase, lactate dehydrogenase) and inflammation (IL-6, TNF-α), as well as muscle soreness, pressure pain threshold (PPT) and muscle function, were measured at baseline; immediately before (pre) and after (0 h) the completion of the exercise-induced muscle damage (EIMD) protocol; and at 24, 48, and 72 h. Results Following the EIMD protocol, muscle soreness peaked at 24 h, while PPT reached its lowest level. The NM group exhibited significantly lower muscle soreness scores (F 3.160 = 5.436, p  = 0.001) and higher PPT values (F 3.160 = 12.580, p  < 0.001) compared to the placebo NM group at 0, 24, 48, and 72 h. Muscle function scores reached their lowest point at 0 h, with the NM group demonstrating significantly higher function scores than the placebo NM group both before the EIMD protocol and at 0 h (F 3.160 = 8.532, p  < 0.001). IL-6 levels peaked at 0 h, with the placebo NM group showing significantly higher IL-6 values compared to the NM group only at the 0 h time point (F 5.160 = 5.377, p  < 0.001). No significant group × time interaction effects were observed for the other variables ( p  > 0.05). Conclusions Three weeks of femoral nerve NM applied to healthy untrained participants had positive effects on the possible negative consequences of DOMS. NM may help alleviate inflammation and muscle damage symptoms and shorten the overall recovery time following DOMS. Trial registration (retrospectively registered): The trial was registered on [03/29/2022] with ClinicalTrials.gov (No: NCT05326893) and conducted according to Consolidated Standards of Reporting Trials (CONSORT) guidelines.