Neuromuscular Deficits Research Articles

Neuromuscular Regeneration of Volumetric Muscle Loss Injury in Response to Agrin-Functionalized Tissue Engineered Muscle Grafts and Rehabilitative Exercise.

Neuromuscular deficits compound the loss of contractile tissue in volumetric muscle loss (VML). Two avenues for promoting recovery are neuromuscular junction (NMJ)-promoting substrates (e.g., agrin) and endurance exercise. Although mechanical stimulation enhances agrin-induced NMJ formation, the two modalities have yet to be evaluated combinatorially. It is hypothesized that the implantation of human myogenic progenitor-seeded tissue-engineered muscle grafts (hTEMGs) in combination with agrin treatment and/or exercise will enhance neuromuscular recovery after VML. The hTEMGs alone transplant into VML defects promote significant regeneration with minimal scarring. A sex-appropriate, low-intensity continuous running exercise paradigm increases acetylcholine receptor (AChR) cluster density in male mice twofold relative to hTEMG alone after 7weeks of treadmill training (p<0.05). To further promote neuromuscular recovery, agrin is incorporated into the scaffolds via covalent tethering. In vitro, agrin increases the proliferation of hMPs, and trends toward greater myogenic maturity and AChR clustering. Upon transplantation, both hTEMGs+agrin and hTEMGs+exercise induce near 100% recovery of muscle mass and increase twitch and tetanic force output (p>0.05). However, agrin treatment in combination with exercise produces no additional benefit. These data highlight the unprecedented regenerative potential of using hTEMGs together with either agrin or exercise supplementation to treat VML injuries.

Frequency of anterior cruciate ligament injuries and their risk factors in young athletes attended at the Orthopedics and Traumatology Center of the city of Rosario (Argentina) in the year 2023

Introduction: The anterior cruciate ligament (ACL) is one of the most important stabilizers of the knee that prevents anterior translation of the tibia over the femur. ACL injuries commonly occur during sports and are usually caused by sudden stops or changes in direction during running, jumping and landing.Objective: To describe the frequency of anterior cruciate ligament injuries and their risk factors in young athletes attended at the Orthopedics and Traumatology Center of the city of Rosario (Argentina) in the year 2023.Materials and methods: Quantitative, descriptive, observational, cross-sectional and retrospective study, carried out at the Orthopedics and Traumatology Center (COT) from April to September 2023. The population consisted of all patients aged between 18 and 25 years, regardless of sex, who practice high-impact sports on the knee and who consulted for knee injury. The collection instrument was the medical records. The variables were summarized through central position measures (mean) and dispersion measures (range and standard deviation) and expressed in absolute and relative frequency.Results: Thirty medical records were analyzed, of which 100% presented some ACL injury. The mean age was 21.57 ± 2.30 years, 67% were male and 33% female. Regarding the type of injury, 63% presented sprain and 37% tear. Twenty-seven percent played field hockey and rugby respectively, 20% played soccer, 13% basketball, 10% tennis and 3% volleyball. The risk factors associated with ACL injuries found in the studied population were among the intrinsic (50%) the neuromuscular deficit (37%) and genetic risk (13%); while among the extrinsic (23%) were the type of footwear (13%) used and the surface of the field (10%).Conclusions: Patients with ACL injuries evaluated were on average 21.57 ± 2.30 years old with a male: female ratio of 2:1. The most common symptoms were walking instability, edema, swelling, and pain. The most common sports associated with anterior cruciate ligament injuries were field hockey, rugby and soccer. Neuromuscular deficit, genetic risk, improper footwear and unstable field surface were found to be risk factors

Fatigue-related changes in intermuscular electromyographic coherence across rotator cuff and deltoid muscles in individuals with and without subacromial pain.

Neuromuscular fatigue induces superior migration of the humeral head in individuals with subacromial pain. This has been attributed to weakness of rotator cuff muscles and overactive deltoid muscles. Investigation of common inputs to motoneuron pools of the rotator cuff and deltoid muscles offers valuable insight into the underlying mechanisms of neuromuscular control deficits associated with subacromial pain. This study aims to investigate intermuscular coherence across the rotator cuff and deltoid muscles during a sustained submaximal isometric fatiguing contraction in individuals with and without subacromial pain. Twenty symptomatic and 18 asymptomatic young adults participated in this study. Surface electromyogram (EMG) was recorded from the middle deltoid (MD) and infraspinatus (IS). Intramuscular EMG was recorded with fine-wire electrodes in the supraspinatus (SS). Participants performed an isometric fatiguing contraction of 30° scaption at 25% maximum voluntary contraction (MVC) until endurance limit. Pooled coherence of muscle pairs (SS-IS, SS-MD, IS-MD) in the 2-5 Hz (delta), 5-15 Hz (alpha), and 15-35 Hz (beta) frequency bands during the initial and final 30 s of the fatigue task were compared. SS-IS and SS-MD delta-band coherence increased with fatigue in the asymptomatic group but not the symptomatic group. In the alpha and beta bands, SS-IS and SS-MD coherence increased with fatigue in both groups. IS-MD beta-band coherence was greater in the symptomatic than the asymptomatic group. Individuals with subacromial pain failed to increase common drive across rotator cuff and deltoid muscles and have altered control strategies during neuromuscular fatigue. This may contribute to glenohumeral joint instability and subacromial pain experienced by these individuals.NEW & NOTEWORTHY Through the computation of shared neural drive across glenohumeral muscles, this study reveals that individuals with subacromial pain were unable to increase shared neural drive within the rotator cuff and across the supraspinatus and deltoid muscles during neuromuscular fatigue induced by sustained isometric contraction. These deficits in common drive across the shoulder muscles likely contribute to the joint instability and pain experienced by these individuals.

Effects of Fatigue on Lower Limb Biomechanics and Kinetic Stabilization During the Tuck-Jump Assessment.

General and local muscular fatigue is postulated to negatively alter lower limb biomechanics; however, few prospective studies have been done to examine the effect of fatigue on tuck-jump performance. The tuck-jump assessment (TJA) is a criteria-based visual screening tool designed to identify neuromuscular deficits associated with anterior cruciate ligament (ACL) injury. Use of kinetics during the TJA after an intense sport-specific fatigue protocol may identify fatigue-induced neuromuscular deficits associated with ACL injury risk. To examine the effects of a sport-specific fatigue protocol on visually evidenced (2-dimensional) technical performance of repeated tuck jumps and lower limb kinetic stabilization. Cross-sectional study. Laboratory. Twelve female netball athletes (age = 20.8 ± 2.6 years, height = 170.0 ± 0.04 cm, mass = 67.5 ± 7.4 kg). Participants performed 1 set of a TJA before and after a sport-specific fatigue protocol. Paired t tests and effect sizes were used to evaluate differences and the magnitude of differences in TJA scoring criterion, kinetics, and kinetic stabilization prefatigue to postfatigue. A small increase was observed for vertical relative lower extremity stiffness postfatigue (P = .005; Hedges g = 0.45). Peak center-of-mass displacement, time of jump cycle, ground contact time, flight time, jump height, and vertical net impulse decreased with small to moderate effect sizes (P < .01; Hedges g range, 0.41-0.74). No differences were observed for TJA composite scores, peak vertical ground reaction force, and stabilization indices of kinetic variables after the fatigue protocol (P > .05). Kinetic analysis of repeated tuck jumps after a fatigue protocol identified an altered jumping strategy, which was not identifiable via visual 2-dimensional assessment. However, based on kinetic measures, fatigue induces a stiffer jumping strategy, and practitioners should consider assessing load attenuation strategies that may not be visually evident when evaluating ACL-injury risk factors in athletes who are fatigued.

Effect of Progressive Balance Control Strategies on Chronic Ankle Instability in Middle-Aged Obese Women.

Chronic ankle instability (CAI) is a disease characterized by persistent feelings of instability in the ankle joint and a propensity for recurrent ankle sprains. It is often caused by ligamentous laxity or neuromuscular deficits. Middle-aged obese females represent a demographic subset at increased risk for CAI due to factors such as reduced proprioception and increased loading on the ankle joint. The gaps in the current evidence suggest that more research is needed on middle-aged obese females, who are particularly vulnerable to CAI due to physiological changes associated with poor balance. This study aims to determine the effect of progressive balance control strategies on CAI in middle-aged obese women. In this experimental study, 72 patients with CAI in middle-aged women were selected randomly using a simple random sampling method. Females aged 35-45 with a body mass index (BMI) greater than 27 kg/m2 and a history of ankle sprains greater than one and having residual symptoms. The experimental group (Group B) received progressive balance control strategies, and the conventional group (Group A) received conventional balance exercises. Foot and ankle ability measure (FAAM) scale, push-and-release test (PART), single-leg stance test (SLST), evaluations, and star excursion balance test (SEBT) were used for pre- and posttreatment. The experimental group post-intervention for static balance, dynamic balance, and postural control tests showed extremely significant improvement with a p-value of <0.0001. Between groups A and B, the dynamic balance was considered very significant, with a p-value of 0.0001. In the single-leg stance test, Group B's result was significantly greater than that ofGroup A's (63.4 + 16.1 and 63.4 + 16.1). PART results indicate that Group B is more significant than Group A (0.76 and 0.51, respectively). The study concluded that progressive balance control strategy training is effective in middle-aged obese women with CAI.

Mutations in the cytoplasmic iron-sulfur assembly protein CIAO1 cause neuromuscular deficits

Mutations in the cytoplasmic iron-sulfur assembly protein CIAO1 cause neuromuscular deficits

Utility of a Neuromuscular Activation Exercise Protocol on Surgeon Posture.

Surgeons are at risk for musculoskeletal disorders from ergonomic strain in the operating room. These deficits may stem from neuromuscular control deficits. Neuromuscular activation exercises (NMEs) may strengthen the brain-muscle connection. This study aimed to assess the utility of a surgeon-oriented NME protocol on posture. Surgeons, operating room staff, and medical students completed a professionally established NME routine. An electronic application, PostureScreen®, assessed participants' posture. A long-term cohort was assessed before and after a 2 to 6-week routine. A short-term cohort was assessed immediately before and after completion. All participants additionally completed a postintervention survey. After intervention, the short-term cohort (n = 47) had significantly reduced frontal and sagittal postural deviation (P < 0.05). A significant decrease in effective head weight was additionally demonstrated with decreased neck flexion and increased cerebral-cervical symmetry (P < 0.05).The long-term cohort (n = 6) showed a significant postintervention decrease in lateral and anterior shoulder translation (P < 0.05). Total anterior translational deviations demonstrated trend-level decrease (P = 0.078). This demonstrates that after intervention, participants' shoulders were more centered with the spine as opposed to shifted right or left. Survey results showed participants favored exercises that immediately brought relief of tension. A decrease in postural deviations associated with NME in both cohorts demonstrates NME as a potential mechanism to protect surgeon musculoskeletal health and improve well-being. Survey results demonstrate areas of refinement for NME protocol design.

Chloroquine Affects Frequency-Dependent Endocytosis in Diaphragm Muscle of Old Mice

Chloroquine is an antimalarial agent commonly used as an autophagy inhibitor by preventing autolysosomal fusion. Autophagy is an important cellular process through which defective cytoplasmic structures are recycled and degraded that has been implicated in aging neuromuscular effects. We recently showed that acute chloroquine treatment blunts the maximal forces generated by the diaphragm muscle, likely by impairing neuromuscular transmission generally consistent with aging effects in the diaphragm muscle. In addition, old mice show increased accumulation of autophagy proteins in phrenic motor neurons, consistent with impaired autophagy flux. In the present study, we hypothesized that chloroquine treatment results in accumulation of bulk endosomes pre-synaptically. Each hemidiaphragm with attached phrenic nerve was excised from 24-month-old male and female C57BL/6 mice to evaluate frequency dependent (0 vs 80 Hz stimulation) uptake of the styryl dye FM4-64, given that 80-Hz stimulation frequency induces bulk endocytosis after synaptic vesicle retrieval. Diaphragm-phrenic nerve preparations were incubated in 5 μM FM4-64 for 1 h prior to 6-min nerve stimulation (0.5 ms supramaximal pulses in 80 Hz, 200 ms trains delivered at 40% duty cycle) followed by a 5-min post-stimulation incubation. FM4-64 uptake at diaphragm neuromuscular junctions (NMJs) was measured using confocal microscopy. Preparations were randomly assigned to co-incubation with chloroquine (50 μM) or vehicle (Rees-Simpson solution). There was minimal FM4-64 uptake in the absence of phrenic nerve stimulation, consistent with the activity-dependent uptake of the styryl dye. With 80 Hz stimulation, high levels of FM4-64 uptake were evident in both the chloroquine and vehicle-treated groups without significant differences across groups. FM4-64 fluorescence was evident throughout the presynpatic terminal with few areas of dense accumulation, consistent with retention of endosomes. There was no evidence of greater endosome accumulation with chloroquine treatment. Of note, a slight increase in FM4-64 uptake was evident in the chloroquine treated groups compared to vehicle in the non-stimulated NMJs. These results are consistent with FM4-64 uptake reflecting bulk endocytosis that mainly occurs during high frequency stimulation. The impairment in autophagy flux following chloroquine treatment is expected to result in endosome accumulation but it is possible that the stimulation protocol was insuffcient to elucidate this possibility. Collectively, the findings of this study are consistent with impaired autophagy at diaphragm presynaptic terminals which may underlie neuromuscular deficits observed in old age. Supported by NIH grant R01 AG057052 and the Mayo Clinic. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sensitive Identification of Asymmetries and Neuromuscular Deficits in Lower Limb Function in Early Multiple Sclerosis

Background In the early stages of multiple sclerosis (MS), there are no objective sensitive functional assessments to identify and quantify early subclinical neuromuscular deficits and lower limb strength asymmetries during complex movements. Single-countermovement jumps (SLCMJ), a maximum single leg vertical jump, on a force plate allow functional evaluation of unilateral lower limb performance in performance diagnostics and could therefore provide early results on asymmetries in MS. Objective Objective evaluation of early lower limb neuromuscular deficits and asymmetries in people with multiple sclerosis (pwMS) using SLCMJ on a force plate. Methods A study was conducted with pwMS (N = 126) and healthy controls (N = 97). All participants performed 3 maximal SLCMJs on a force plate. Temporal, kinetic, and power jump parameters were collected. The Expanded Disability Status Scale (EDSS) was performed on all participants. A repeated measures analysis of covariance (ANCOVA) with age, Body-Mass-Index, and gender as covariates was used. Results PwMS with normal muscle strength according to the manual muscle tests showed significantly reduced SLCMJ performance compared to HC. In both groups, jumping performance differed significantly between the dominant and non-dominant leg, with higher effect size for pwMS. A significant interaction effect between leg dominance and group was found for propulsive time, where the pwMS showed an even higher difference between the dominant and non-dominant leg compared to HC. Furthermore, there was a significant small correlation between leg asymmetries and EDSS in pwMS. Conclusion The study shows that the SLCMJ on a force plate is suitable for the early detection of subclinical lower limb neuromuscular deficits and strength asymmetries in MS.

Joint kinematics and SPM analysis of gait in children with and without Down syndrome

BackgroundIndividuals with Down syndrome (DS) walk with altered gait patterns compared to their typically developing (TD) peers. While walking at faster speeds and with external ankle load, preadolescents with DS demonstrate spatiotemporal and kinetic improvements. However, evidence of joint kinematic adjustments is unknown, which is imperative for targeted rehabilitation design. Research questionHow does increasing walking speed and adding ankle load affect the joint kinematics of children with and without DS during overground walking? MethodsIn this cross-sectional observational study, thirteen children with DS aged 7–11 years and thirteen age- and sex-matched TD children completed overground walking trials. There were two speed conditions: normal speed and fast speed (as fast as possible without running). There were two load conditions: no load and ankle load (2% of body mass added bilaterally above the ankle). A motion capture system was used to register the ankle, knee, and hip joint angles in the sagittal plane. Peak flexion/extension angles, range of motion, and timing of peak angles were identified. In addition, statistical parametric mapping (SPM) was conducted to evaluate the trajectory of the ankle, knee, and hip joint angles across the entire gait cycle. Results and significanceSPM analysis revealed the DS group walked with greater ankle, knee, and hip flexion compared to the TD group for most of the gait cycle, regardless of condition. Further, increasing walking speed led to improved ankle joint kinematics in both groups by shifting peak plantarflexion closer to toe-off. However, knee extension during stance was challenged in the DS group. Adding ankle load improved hip and knee kinematics in both groups but reduced peak plantarflexion around toe-off. The kinematic adjustments in the DS group suggest specific motor strategies to accommodate their neuromuscular deficits, which can provide a foundation to design targeted gait-based interventions for children with DS.

Neural consequences of symptomatic convergence insufficiency: A small sample study.

Convergence insufficiency (CI) is an oculomotor abnormality characterised by exophoria and inadequate convergence when focusing on nearby objects. CI has been shown to cause symptoms when reading. However, the downstream consequences on brain structure have yet to be investigated. Here, we investigated the neural consequences of symptomatic CI, focusing on the left arcuate fasciculus, a bundle of white matter fibres which supports reading ability and has been associated with reading deficits. We compared the arcuate fasciculus microstructure of participants with symptomatic CI versus normal binocular vision (NBV). Six CI participants and seven NBV controls were included in the analysis. All participants were scanned with 3 T magnetic resonance imaging (MRI), and anatomical and diffusion-weighted images were acquired. Diffusion-weighted images were processed with TRACULA to identify the arcuate fasciculus in each participant and compute volume and radial diffusivity (RD). Compared with NBV controls, those with symptomatic CI had significantly smaller arcuate fasciculi bilaterally (left: t = -3.21, p = 0.008; right: t = -3.29, p = 0.007), and lower RD in the left (t = -2.66, p = 0.02), but not the right (t = -0.81, p = 0.44, false discovery rate (FDR)-corrected p > 0.05) arcuate fasciculus. Those with higher levels of reading symptoms had smaller arcuate fasciculi (r = -0.74, p = 0.004) with lower RD (r = -0.61, p = 0.03). These findings suggest that symptomatic CI may lead to microstructural changes in the arcuate fasciculus. Since it is highly unlikely that abnormalities in the arcuate fasciculus are the cause of the neuromuscular deficits in the eyes, we argue that these changes may be a potential neuroplastic consequence of disruptions in sustained reading.

Utilising dynamic motor control index to identify age-related differences in neuromuscular control

PurposeConsidering the relationship between aging and neuromuscular control decline, early detection of age-related changes can ensure that timely interventions are implemented to attenuate or restore neuromuscular deficits. The dynamic motor control index (DMCI), a measure based on variance accounted for (VAF) by one muscle synergy (MS), is a metric used to assess age-related changes in neuromuscular control. The aim of the study was to investigate the use of one-synergy VAF, and consecutively DMCI, in assessing age-related changes in neuromuscular control over a range of exercises with varying difficulty. MethodsThirty-one subjects walked on a flat and inclined treadmill, as well as performed forward and lateral stepping up tasks. Motion and muscular activity were recorded, and muscle synergy analysis was conducted using one-synergy VAF, DMCI, and number of synergies. ResultsDifference between older and younger group was observed for one-synergy VAF, DMCI for forward stepping up task (one-synergy VAF difference of 2.45 (0.22, 4.68) and DMCI of 9.21 (0.81, 17.61), p = 0.033), but not for lateral stepping up or walking. ConclusionThe use of VAF based metrics and specifically DMCI, rather than number of MS, in combination with stepping forward exercise can provide a low-cost and easy to implement approach for assessing neuromuscular control in clinical settings.

The DDHD2-STXBP1 interaction mediates long-term memory via generation of saturated free fatty acids.

The phospholipid and free fatty acid (FFA) composition of neuronal membranes plays a crucial role in learning and memory, but the mechanisms through which neuronal activity affects the brain's lipid landscape remain largely unexplored. The levels of saturated FFAs, particularly of myristic acid (C14:0), strongly increase during neuronal stimulation and memory acquisition, suggesting the involvement of phospholipase A1 (PLA1) activity in synaptic plasticity. Here, we show that genetic ablation of the PLA1 isoform DDHD2 in mice dramatically reduces saturated FFA responses to memory acquisition across the brain. Furthermore, DDHD2 loss also decreases memory performance in reward-based learning and spatial memory models prior to the development of neuromuscular deficits that mirror human spastic paraplegia. Via pulldown-mass spectrometry analyses, we find that DDHD2 binds to the key synaptic protein STXBP1. Using STXBP1/2 knockout neurosecretory cells and a haploinsufficient STXBP1+/- mouse model of human early infantile encephalopathy associated with intellectual disability and motor dysfunction, we show that STXBP1 controls targeting of DDHD2 to the plasma membrane and generation of saturated FFAs in the brain. These findings suggest key roles for DDHD2 and STXBP1 in lipid metabolism andin the processes of synaptic plasticity, learning, and memory.

The influence of jump-landing direction on dynamic postural stability following anterior cruciate ligament reconstruction

BackgroundTraditional testing prior to return to sport following anterior cruciate ligament reconstruction typically involves jump-landing tasks in the forward direction. As injury is most likely the result of multiplanar neuromuscular control deficits, assessment of dynamic postural stability using landing tasks that require multiplanar stabilization may be more appropriate. The purpose of this study was to examine how dynamic postural stability is affected when performing jump-landing tasks in three different directions. MethodsFifteen athletes [11 females (18.0 ± 3.0 years) and 4 males (18.5 ± 3.1 years)] following anterior cruciate ligament reconstruction performed a series of single-limb jump-landing tasks in 3 directions. Individual directional stability indices and a composite dynamic postural stability index were calculated using ground reaction force data and were compared using separate one-way repeated measures ANOVAs. FindingsAll directional stability indices demonstrated a significant main effect for jump-landing direction (medial-lateral P < 0.001, η2p = 0.95; anterior-posterior P < 0.001, η2p = 0.97; vertical P = 0.021, η2p = 0.24). The diagonal jump-landing direction produced increased medial-lateral stability and vertical stability scores, while the forward and diagonal jump-landing directions produced increased anterior-posterior stability scores. There was no significant effect for the composite dynamic stability index score. InterpretationJump-landing direction affects dynamic postural stability in all 3 planes of movement in athletes following anterior cruciate ligament reconstruction. Results indicate the potential need to incorporate multiple jump-landing directions to better assess dynamic postural stability prior to return to sport.

High magnitude exposure to repetitive head impacts alters female adolescent brain activity for lower extremity motor control

Contact and collision sport participation among adolescent athletes has raised concerns about the potential negative effects of cumulative repetitive head impacts (RHIs) on brain function. Impairments from RHIs and sports-related concussions (SRC) may propagate into lingering neuromuscular control. However, the neural mechanisms that link RHIs to altered motor control processes remain unknown. The purpose of this study was to isolate changes in neural activity for a lower extremity motor control task associated with the frequency and magnitude of RHI exposure. A cohort of fifteen high school female soccer players participated in a prospective longitudinal study and underwent pre- and post-season functional magnetic resonance imaging (fMRI). During fMRI, athletes completed simultaneous bilateral ankle, knee, and hip flexion/extension movements against resistance (bilateral leg press) to characterize neural activity associated with lower extremity motor control. RHI data were binned into continuous categories between 20 g − 120 g (defined by progressively greater intervals), with the number of impacts independently modeled within the fMRI analyses. Results revealed that differential exposure to high magnitude RHIs (≥90 g - < 110 g and ≥ 110 g) was associated with acute changes in neural activity for the bilateral leg press (broadly inclusive of motor, visual, and cognitive regions; all p < 0.05 & z > 3.1). Greater exposure to high magnitude RHIs may impair lower extremity motor control through maladaptive neural mechanisms. Future work is warranted to extend these mechanistic findings and examine the linkages between RHI exposure and neural activity as it relates to subsequent neuromuscular control deficits.

Effects of 1-hour computer use on ulnar and median nerve conduction velocity and muscle activity in office workers.

To compare the effects of 1-hour computer use on ulnar and median nerve conduction velocity and muscle activity in office workers with symptomatic neck pain and asymptomatic office workers. A total of 40 participants, both male and female office workers, with symptomatic neck pain (n = 20) and asymptomatic (n = 20), were recruited. Pain intensity, ulnar nerve conduction velocity, median nerve conduction velocity, and muscle activity were determined before and after 1 hour of computer use. There was a significant increase in pain intensity in the neck area in both groups (P < .001). The symptomatic neck pain group revealed a significant decrease in the sensory nerve conduction velocity of the ulnar nerve (P = .008), whereas there was no difference in the median nerve conduction velocity (P > .05). Comparing before and after computer use, the symptomatic neck pain group had less activity of the semispinalis muscles and higher activity of the anterior scalene muscle than the asymptomatic group (P < .05). The trapezius and wrist extensor muscles showed no significant differences in either group (P > .05). This study found signs of neuromuscular deficit of the ulnar nerve, semispinalis muscle, and anterior scalene muscle after 1hour of computer use among office workers with symptomatic neck pain, which may indicate the risk of neuromuscular impairment of the upper extremities. The recommendation of resting, and encouraging function and flexibility of the neuromuscular system after 1hour of computer use should be considered.

Virtual Neuromuscular Training Among Physically Active Young Adults: A Feasibility Study.

Evidence indicates a 2 to 3 times increased risk of musculoskeletal injury after return to play from concussion. Undetected neuromuscular control deficits at return to play may relate to increased musculoskeletal injury risk. Rehabilitation to improve neuromuscular control may benefit patients with concussion, but access to rehabilitation professionals and/or poor adherence may limit efficacy. Our purpose was to determine the feasibility of an 8-week virtual neuromuscular training (NMT) program administered through a novel smartphone application among physically active, uninjured adults. Feasibility trial. Participants were instructed to complete an NMT program administered via a smartphone application and returned for follow-up questionnaires 8weeks later. They were instructed to complete 3 asynchronous self-guided workouts per week during the 8-week intervention period. Workouts included balance, plyometrics, strengthening, and dual-task exercises. The application provided instructions for each exercise using video, text, and audio descriptions. Our primary feasibility measure was participant adherence, calculated as the percentage of workouts completed out of the total possible 24 workouts. We recorded the average duration of each workout using start/stop/advance features within the application. Twenty participants were enrolled, of which 15 (age = 26.3 [2.7]y, 67% female) returned for follow-up (75% retention). Participant adherence was 57.2% (25.0%; range: 16.7%-91.7%). Participants spent 17.3 (8.0)minutes per workout (range: 7.4-37.9min). There were no adverse reactions or injuries. Most participants (60%) reported time availability as a primary barrier to intervention completion. Participants were moderately (>50%) adherent to a virtual NMT program, without any reported injuries. We identified several barriers to participation and pathways for improved adherence in the future. The virtual NMT program completed by uninjured adults provides evidence of its feasibility and future scalability to those with a recent concussion to address neuromuscular control deficits and reduce future injury risk.

Investigating the Application of Orem’s Self-care Nursing Theory for Spinal Muscular Atrophy: A Case Study Design

Background: Spinal muscular atrophy (SMA) is a neuromuscular disorder that is highly frequent in children. This leads to serious health challenges for children of different severity levels. Orem’s self-care deficit nursing theory helps parents get involved in their child’s care, leading to better outcomes and healthcare experiences. Accordingly, this case study examines the effectiveness of applying Orem’s self-care nursing theory to a child with SMA and his parents. Case Presentation: This study used Orem’s self-care deficit nursing theory to treat particular self-care deficiencies relating to mobility, eating, swallowing, and respiratory function in a 3-year-old child with SMA type I. The researcher recognized the patient’s lack of self-care and created a tailored plan for self-management training. The initial steps were to understand the patient’s needs, organize the implementation, and create the educational system. The final phase entailed implementing the self-care program and assessing its success. The following methods were used to gather the data: Structured interviews and surveys on Orem’s theory and self-care ability. A 60-min educational intervention was broken up into four in-person sessions. This study illustrates the useful application of theories in illness management. This theory was used to identify deficiencies in movement, feeding, swallowing, and respiratory function. Nursing interventions focused on neuromuscular deficits, while educational interventions enhanced parents’ awareness. Conclusions: This case study investigates the usefulness of Orem’s theory in controlling SMA, empowering parents, emphasizing patient-centered care, and the possible advantages of nursing theories in treating chronic diseases.

Chronic Ankle Instability and Neuromuscular Performance in Prerecruitment Infantry Soldiers.

Ankle instability can describe various impairments, including perceived instability (PI), mechanical instability (MI), and recurrent sprains (RSs), alone or combined. To examine the prevalence of 8 ankle impairment subgroups and their effect on neuromuscular performance in prerecruitment combat soldiers. Cross-sectional study. Military infantry basic training base. A total of 364 infantry male combat soldiers entering basic training (aged 18-21 years). Participants were assessed for PI (via the Cumberland Ankle Instability Tool), MI (using the Anterior Drawer Test and Medial Talar Tilt Test), and RSs (based on history) of their dominant and nondominant legs. Injuries were categorized in 8 subgroups: PI, RSs, PI + RSs, MI, PI + MI, MI + RSs, PI + MI + RSs, and none. Participants were screened for neuromuscular performance (dynamic postural balance, proprioceptive ability, hopping agility, and triceps surae muscle strength) during the first week of military basic training. For the dominant and nondominant legs, RSs were reported by 18.4% (n = 67) and 20.3% (n = 74) of the participants, respectively; PI was reported by 27.1% (n = 99) and 28.5% (n = 104) of the participants, respectively; and MI was seen in 9.9% (n = 36) and 8.5% (n = 31) of the participants, respectively. A 1-way analysis of variance showed differences in the mean proprioceptive ability scores (assessed using the Active Movement Extent Discrimination Apparatus) of all subgroups with impairments in both the dominant and nondominant legs (F = 6.943, η2 = 0.081, P < .001 and F = 7.871, η2 = 0.091, P < .001, respectively). Finally, differences were found in the mean muscle strength of subgroups with impairment in the nondominant leg (F = 4.884, η2 = 0.056, P = .001). A high prevalence of ankle impairments was identified among participants who exhibited reduced abilities in most neuromuscular assessments compared with those who did not have impairments. Moreover, participants with 1 impairment (PI, MI, or RSs) exhibited different neuromuscular performance deficits than those with >1 impairment.

Analysis of the neuromuscular deficits caused by STAM1 deficiency

The endosomal sorting complexes required for transport (ESCRT) pathway is composed of a series of protein complexes that are essential for sorting cargo through the endosome. In neurons, the ESCRT pathway is a key mediator of many cellular pathways that regulate neuronal morphogenesis as well as synaptic growth and function. The ESCRT-0 complex, consisting of HGS (hepatocyte growth factor-regulated tyrosine kinase substrate) and STAM (signal-transducing adaptor molecule), acts as a gate keeper to this pathway, ultimately determining the fate of the endosomal cargo. We previously showed that a single nucleotide substitution in Hgs results in structural and functional changes in the nervous system of teetering mice. To determine if these changes occurred as a function of HGS's role in the ESCRT pathway and its association with STAM1, we investigated if STAM1 deficiency also leads to a similar impairment of the nervous system. In contrast to teetering mice that die within 5 weeks of age and exhibit reduced body mass, 1-month-old Stam1 knockout mice were not visibly different from controls. However, by 3 months of age, STAM1 deficiency caused reduced muscle mass, strength, and motor performance. These changes in motor function did not correlate with either a loss in motor neuron number or abnormal myelination of peripheral nerves. Instead, the motor endplate structure was altered in the Stam1 knockout mice by 1 month of age and continued to degenerate over time, correlating with a significant reduction in muscle fiber size and increased expression of the embryonic γ acetylcholine receptor (AChR) subunit at 3 months of age. There was also a significant reduction in the levels of two presynaptic SNARE proteins, VTI1A and VAMP2, in the motor neurons of the Stam1 knockout mice. As loss of STAM1 expression replicates many of the structural changes at the motor endplates that we have previously reported with loss of HGS, these results suggest that the HGS/STAM1 complex plays a critical role in maintaining synaptic structure and function in the mammalian nervous system.