This single-arm pilot study evaluates the effects of whole-body electrical muscle stimulation (WB-EMS) exercise on neuromuscular and physical function in adults with neuromuscular disease (NMD). Due to motor unit impairments, NMD patients often cannot tolerate traditional exercise. WB-EMS bypasses voluntary activation limits by directly stimulating muscle contractions. Up to 50 adults with conditions like ALS, SMA, and MG will undergo 20-minute supervised WB-EMS sessions (1-2 times weekly for 4-8 weeks) using the Katalyst system. Outcomes include neural excitability (TMS), motor unit behavior (EMG, NCS), functional tests (walk, balance, strength), and patient-reported fatigue, pain, and quality of life. Strict safety monitoring and exclusion criteria are in place. This study will provide preliminary data on WB-EMS as a potential exercise modality for NMD.

This single-arm pilot study aims to investigate the effects of a whole-body electrical muscle stimulation (WB-EMS) exercise program on neuromuscular and physical function in adults with neuromuscular disease (NMD). The background rationale is that individuals with NMD often experience significant barriers to traditional exercise due to impaired voluntary motor unit activation, leading to sedentary behavior, physical deconditioning, and worsened long-term health outcomes. WB-EMS may offer a therapeutic alternative by bypassing voluntary activation limits and directly stimulating muscle contractions through externally applied electrical currents. The intervention utilizes the Katalyst system, an FDA-cleared device being used off-label in this population, which delivers targeted stimulation to major muscle groups during synchronized exercise movements. Up to 50 adults diagnosed with various NMDs, including amyotrophic lateral sclerosis, spinal muscular atrophy, myasthenia gravis, and Charcot-Marie-Tooth disease, will be enrolled. Eligible participants must be at least 18 years old, able to stand continuously for 15 minutes with or without assistance, and have at least anti-gravity strength in major muscle groups. Key exclusion criteria include implanted electrical devices, unstable medical conditions, pregnancy, and conditions affecting muscle fiber structural integrity. The intervention consists of 20-minute supervised exercise sessions performed 1-2 times per week over 4-8 weeks, with real-time monitoring of pain, perceived exertion, and tolerability. Outcome measures include neural excitability assessed via transcranial magnetic stimulation, voluntary motor unit characteristics via decomposition electromyography, stimulated motor unit characteristics via compound muscle action potential nerve conduction study, functional performance tests (10-meter walk, timed up and go, five-time sit-to-stand, stair ascent/descent, broad jump, multidirectional lunge), and patient-reported outcomes evaluating fatigue, pain, and quality of life. This pilot study will generate critical preliminary data on the feasibility, safety, and efficacy of WB-EMS as a novel exercise modality for adults with NMD, with the goal of informing future large-scale clinical trials.

Inclusion Criteria:

• Age 18 or older
• Diagnosed with one or more of the following neuromuscular conditions: Amyotrophic lateral sclerosis, primary lateral sclerosis, progressive muscle atrophy, spinal muscular atrophy, postpolio syndrome, inclusion body myositis, pompedisease, fascioscapulohumeral muscular dystrophy, charcot marie tooth disease, chronic inflammatory demyelinating polyneuropathy, hereditary spastic paraplegia, myasthenia gravis, lambert-eaton myasthenic syndrome, postural orthostatic tachycardia syndrome, mitochondrial myopathy, nemaline myopathy, centronuclear myopathy, lumbar radiculopathy, non-specific low back pain.
• Ability to stand for approximately 15 minutes continuously with or without an assistive device (i.e. the length of time to stand to take a shower, complete meal preparation, wait in line at the bank, etc.)
• At least some anti-gravity strength in major muscle groups as assessed by manual muscle testing (i.e. 2+/5 strength or better)
• Medical clearance to participate in an exercise program
• Ability to provide informed consent
• Ability to conform to the requirements of the study (i.e. attendance at assessment and intervention visits, maintain current level of non-study physical activity for the duration of the study, no intention to relocate mid-study)

Exclusion Criteria:

• Diagnosed with one of the following neuromuscular conditions: Becker's muscular dystrophy, Duchenne muscular dystrophy, limb-girdle muscular dystrophy, myotonic dystrophy type 1 or 2, Freidrich's ataxia, any other NMD with known or suspected cardiac involvement or muscle fiber structural integrity defects.
• Concurrent participation in another interventional research study
• Unable to tolerate 15 minutes of continuous standing with or without an assistive device
• Presence of a pacemaker, metal implants, or other implanted medical devices that could impact participant safety during WB-EMS intervention
• Presence of cochlear implant, cortical stimulator, deep brain stimulator, ventriculoperitoneal shunt, recent skull defect, seizure in the past 12 months while taking anti-epilepsy medication, or previous serious adverse event with TMS, which could impact participant safety during TMS testing
• Presence of unstable acute or chronic disease (i.e. renal failure, rheumatologic disease, cardia arrhythmia, neoplasm, uncontrolled hypertension)
• Known pregnancy at time of screening; verbal screening will occur throughout the study.
• Presence of a terminal disease (i.e. receiving hospice services)
• Current or previous use of any drugs known to influence muscle mass or performance within 6 months; these may include but are not limited to anabolic steroids, IGF01, growth hormone, replacement androgen therapy, anti-androgen therapy
• Presence of an additional neurologic conditions affecting somatosensory or motor function/control (i.e. Parkinson's disease, Multiple Sclerosis, h/o stroke, TBI, SCI, ataxia, apraxia, hemiplegia, etc.)
• Musculoskeletal condition or surgery in the past year that would confound results of exercise interventions (i.e. TKA, THA, RTC repair, spinal fusion)
• Other medical conditions, signs, or symptoms that would interfere with study conductor interpretation of results as determined by an investigator