Physical Therapy for Genetic Disorders

In type III SMA, independent walking is initially preserved, but difficulties with standing up, climbing stairs, and walking for prolonged periods may emerge over time.

Type IV SMA usually manifests in adulthood and is characterized by relatively slow progression.

Sensation is generally preserved. The diagnosis is confirmed by molecular genetic testing of SMN1, with determination of SMN2 copy number.

3. Goals of Medical Rehabilitation

The rehabilitation program for SMA is determined less by the formal disease type than by the patient's current motor abilities.

The main objectives include:

maintaining acquired motor skills and facilitating the development of new ones during disease-modifying treatment;

preventing contractures, spinal deformities, and complications of prolonged sitting;

preserving upper-limb function;

improving head control, trunk stability, and balance;

ensuring safe mobility and the greatest possible independence;

preventing respiratory complications.

Objective assessment of changes in the patient's condition is particularly important. Specialized scales, including CHOP INTEND, HFMSE, and RULM, are used for this purpose; the choice depends on the patient's age and motor status.

Rehabilitation outcomes are assessed through changes in specific skills, not solely through increases in muscle strength.

4. Therapeutic Exercise

Therapeutic exercise for SMA is organized around three functional categories: patients unable to sit independently, those able to sit, and those able to walk.

For non-sitters, emphasis is placed on appropriate positioning, head and trunk support, preservation of joint mobility, and creating opportunities for independent activity within the patient's capabilities. Gentle passive and active-assisted movements and safe changes of body position are used.

For sitters, the program includes seated balance exercises, pelvic positioning control, functional arm movements, and weight shifting. Standing frames and adapted standing support devices are used when indicated.

For ambulant patients, training includes rising to stand, graded walking, balance exercises, and negotiating small obstacles. Moderate aerobic activity is permissible when adequately tolerated.

Children receiving disease-modifying treatment warrant particular attention: improvements in motor abilities require reassessment of previous functional limitations and the setting of new rehabilitation goals.

Exercise intensity must match residual motor abilities and must not cause pronounced exhaustion.

5. Massage and Device-Based Physical Therapy

Massage in SMA may be used to reduce associated discomfort, facilitate care, and improve tolerance of positioning.

For patients with pronounced muscle atrophy, predominantly gentle techniques are used. Intensive kneading of weakened muscles does not restore motor neurons and should not be regarded as a method of increasing muscle mass.

TENS may be considered for certain associated pain syndromes, such as those related to prolonged sitting or orthopedic complications.

NMES requires particular caution. Because SMA involves lower motor neuron damage and denervation of muscle fibers, the effectiveness of standard neuromuscular electrical stimulation protocols may be limited.

Therapeutic ultrasound, infrared therapy, and magnetotherapy have no proven effect on the course of SMA. Their use for independent symptomatic indications must not replace therapeutic exercise, positioning, or respiratory support.

6. Orthopedic and Functional Rehabilitation

Orthopedic management is particularly important in SMA because of the high likelihood of scoliosis, contractures, and hip joint instability.

For patients who spend long periods sitting, pelvic position, trunk symmetry, and spinal condition must be monitored.

Individually fitted wheelchairs with trunk supports, headrests, and positioning accessories can improve stability and expand opportunities for independent activity.

Orthoses, standing frames, and transfer aids are used when indicated. Surgical treatment may be considered for pronounced spinal deformities, with mandatory assessment of respiratory risks.

Functional rehabilitation includes training in the use of available arm movements, workplace adaptation, and selection of alternative interfaces for controlling devices.

An important task for the specialist is not merely to correct deformities but also to create opportunities for the patient's participation in education, communication, and daily life.

7. Rehabilitation for Systemic and Associated Impairments

The most serious associated problems in SMA involve respiratory insufficiency, ineffective coughing, and swallowing difficulties.

Weakness of the intercostal muscles restricts chest expansion. In severe forms, breathing relies to a considerable extent on the diaphragm, which may be accompanied by paradoxical chest movements.

Respiratory monitoring includes assessment of cough effectiveness, pulmonary ventilation, and signs of nocturnal hypoventilation. Mechanical cough assistance and noninvasive ventilation are used when indicated.

Swallowing disorders require assessment of feeding safety because aspiration increases the risk of infectious complications. Specialized nutritional support may be required if nutritional intake is inadequate.

Current treatment of 5q-SMA includes nusinersen, risdiplam, and gene replacement therapy with onasemnogene abeparvovec for patients who meet the established indications. These treatments alter the natural course of the disease but do not eliminate the need for long-term rehabilitation support.

8. Contraindications and Limitations

In rehabilitation of patients with SMA, the degree of muscle weakness, respiratory reserve, and severity of orthopedic impairments must be considered above all.

Exercises that cause pronounced exhaustion, deterioration of breathing, or a prolonged reduction in motor activity after the session are unacceptable.

In the presence of severe osteoporosis, spinal deformities, or joint instability, traumatic manipulations and uncontrolled axial loading should be avoided.

Standing programs require assessment of tolerance of the upright position, joint condition, and fall risk.

In cases of acute respiratory infection, pronounced breathing difficulty, or signs of hypoventilation, the exercise program must be reassessed.

Particular attention is required in patients with swallowing difficulties and an increased risk of aspiration.

9. Recommendations for Patients and Families

Family members should understand that the effectiveness of home rehabilitation is determined not by the number of exercise repetitions but by how well the exercises match the patient's functional status.

For children with pronounced weakness, it is important to change body position regularly, monitor skin condition, and ensure comfortable positioning of the head, trunk, and limbs.

Patients who can sit should be given opportunities for independent play, learning, and activities using available hand movements.

When walking ability is preserved, safe daily activity should be maintained while avoiding excessive fatigue.

The family should recognize signs of respiratory deterioration: a weakened cough, difficulty clearing secretions, unusual sleepiness, and disturbed breathing during sleep.

Patients receiving disease-modifying therapy require regular reassessment of motor abilities. The emergence of new skills calls for timely adaptation of the home program.

10. Conclusion

Spinal muscular atrophy occupies a special place among hereditary neuromuscular diseases because modern disease-modifying therapies can substantially change a patient's motor prognosis.

The rehabilitation strategy is based on a functional approach that considers the ability to sit, stand, walk, and independently perform daily activities.

The rehabilitation specialist's role is not only to prevent secondary complications but also to make timely use of new motor abilities emerging during treatment.

Vladimir Maletskyi | 36.6 — 366 Days a Year | Physical Therapy for Genetic Disorders

Chapter 8. Charcot–Marie–Tooth Disease

Part II. Hereditary Disorders of the Nervous System

Charcot–Marie–Tooth Disease (CMT)

1. General Characteristics of the Disease

Charcot–Marie–Tooth disease is a group of hereditary disorders of the peripheral nervous system characterized by progressive impairment of motor and sensory innervation, predominantly in the distal parts of the limbs.

The pathological process may affect the myelin sheath of nerve fibers or the axons themselves. Depending on the mechanism of damage, demyelinating, axonal, and intermediate forms of CMT are distinguished.

The disease is genetically highly heterogeneous. The most common form, CMT1A, is associated with duplication of a chromosomal region containing the PMP22 gene. Other forms result from variants in MPZ, GJB1, MFN2, and many other genes. Inheritance may be autosomal dominant, autosomal recessive, or X-linked.

The prevalence of CMT has traditionally been estimated at approximately 1 in 2,500 people. According to a meta-analysis published in 2023, the pooled prevalence of CMT and related hereditary peripheral neuropathies is approximately 17.7 per 100,000 population. Differences between estimates reflect the populations studied, diagnostic criteria, and case ascertainment. This is one of the most common groups of hereditary neurological disorders.

2. Clinical Presentation

Initial symptoms often appear in childhood or adolescence, although some forms manifest considerably later.

Characteristic features include weakness of the foot and lower-leg muscles, difficulty with ankle dorsiflexion, frequent tripping, and steppage gait—a walking pattern involving exaggerated lifting of the leg to prevent the toes from catching on the ground.

Pes cavus (high-arched foot), hammertoes, and ankle instability may develop gradually. Atrophy of the lower-leg muscles sometimes gives the legs a characteristic inverted champagne bottle appearance.

Reduced superficial and vibration sensation impairs awareness of foot position, especially when walking in darkness or on uneven ground. Tendon reflexes are usually diminished.

When the upper limbs are involved, difficulties arise with buttoning clothes, writing, and manipulating small objects.

Diagnosis includes neurological examination, electrodiagnostic studies, and molecular genetic testing.

3. Goals of Medical Rehabilitation

The principal challenge in CMT rehabilitation is the need to compensate for both motor weakness and sensory loss.

The main objectives are:

improving stability during standing and walking;

compensating for weakness of the ankle dorsiflexors;

maintaining the available strength of distal limb muscles;

preventing progression of contractures and the functional consequences of foot deformities;

preserving precision of hand movements;

reducing the risks of falls, skin injuries, and joint overload.

When setting functional goals, it is important to assess not only muscle strength but also walking speed, footwear condition, fall frequency, and the patient's ability to perform daily activities.

The CMTNS and CMTES scales may be used for objective assessment, and CMTPedS may be used in children.

4. Therapeutic Exercise

Therapeutic exercise aims to maintain the functional capacity of preserved muscles, improve balance, and correct altered movement patterns.

For ankle dorsiflexor weakness, active dorsiflexion exercises with light resistance are used if the remaining muscle function permits the movement. Ankle position control and weight shifting are also trained.

Balance exercises take impaired proprioception into account. Initially, stable support and visual feedback are used, with tasks gradually becoming more challenging while maintaining safety.

Regular gentle calf stretching is used to prevent shortening of the Achilles tendon. Where deformities are already established, the range of motion is determined individually.

Hand training includes finger abduction, controlled grasping of objects of different shapes, and exercises for movement precision and coordination.

Moderate resistance and aerobic activities, including stationary cycling, swimming, and graded walking, may improve physical fitness. In patients with pronounced weakness, overloading individual muscle groups should be avoided, and recovery after exercise should be monitored.

5. Massage and Device-Based Physical Therapy

In CMT, massage may be used to relieve associated musculoskeletal pain, particularly pain arising from altered gait and redistribution of loads across the joints.

When sensation is reduced, the practitioner must control pressure intensity because the patient may not always recognize excessive mechanical force in time.

TENS may be considered for selected pain syndromes. Musculoskeletal pain must be distinguished from neuropathic pain because symptomatic interventions do not have the same effectiveness in these conditions.

The potential effectiveness of NMES depends on peripheral nerve integrity and the degree of muscle denervation. In pronounced axonal disease, standard stimulation may be of limited benefit. NMES is not an established means of restoring damaged nerve fibers in CMT.

There is no convincing evidence that therapeutic ultrasound, infrared therapy, or magnetotherapy can slow CMT progression. Their use for associated pain requires separate justification; particular caution is needed when temperature and pain sensation are impaired.

6. Orthopedic and Functional Rehabilitation

Orthopedic management in CMT has a direct impact on walking quality.

For foot drop, individually fitted ankle-foot orthoses (AFOs) improve foot positioning during the swing phase and reduce the risk of tripping.

For pes cavus and ankle instability, orthopedic footwear and insoles are selected to distribute loads more evenly. Areas of excessive pressure on the foot must be checked regularly.

Surgical correction may be considered for pronounced fixed deformities. Decisions are based on assessment of muscle balance, deformity flexibility, and the anticipated functional outcome.

For patients with hand weakness, adapted writing implements, enlarged handles, and aids that facilitate household tasks are used.

Orthopedic devices should be evaluated during movement: even a technically well-made orthosis does not always produce an optimal gait for an individual patient.

7. Rehabilitation for Systemic and Associated Impairments

In most common forms of CMT, peripheral sensorimotor neuropathy remains the principal problem. Significant involvement of the heart and respiratory muscles is not an obligatory feature of the disease.

However, certain rare genetic variants may cause respiratory weakness, sleep disturbances, vocal fold involvement, and additional neurological symptoms.

Unexplained shortness of breath, nocturnal hypoventilation, voice changes, or stridor require specialist assessment.

Neuropathic pain deserves particular attention and may present as burning, tingling, or painful sensations in the feet and hands.

Pain management must address its underlying cause. Severe neuropathic pain may require specific pharmacological treatment, whereas mechanical pain caused by foot deformity may call for adjustments to orthopedic support.

8. Contraindications and Limitations

Particular caution is required during rehabilitation in patients with pronounced impairment of pain, temperature, and proprioceptive sensation.

Intensive heat treatments, excessive pressure, and traumatic manipulations may cause tissue damage that the patient does not notice promptly.

Exercises with a high risk of falling should be avoided without appropriate support, especially when foot-position control is impaired.

In the presence of pronounced deformities, prolonged weight-bearing in unsuitable footwear is inadvisable. Chafing, redness, or tenderness requires reassessment of orthoses and adjustment of the activity regimen.

Exercises causing prolonged deterioration in muscle function must be reconsidered. When treating comorbid conditions, physicians should take into account the potential neurotoxicity of certain medications.

9.Recommendations for Patients and Families

Patients with CMT are advised to inspect their feet daily, especially when sensation is markedly reduced. Skin injuries, calluses, and areas of excessive pressure should be identified promptly.

Footwear should match the shape of the feet, provide stability, and avoid additional friction. The fit of orthoses should be checked periodically.

To improve safety at home, good lighting, removal of floor obstacles, and handholds in areas with increased fall risk are advisable.

For hand weakness, adapting household items helps preserve independence without constant assistance from family members.

Because CMT comprises a group of hereditary diseases, genetic counseling may be recommended for patients and their relatives.

10. Conclusion

Charcot–Marie–Tooth disease is characterized by the combination of distal muscle weakness, sensory impairment, and characteristic orthopedic changes in the feet.

The practical value of rehabilitation lies primarily in gait correction, timely selection of orthoses, preservation of hand function, and prevention of complications related to reduced sensation.

The rehabilitation program should take account of the specific genetic subtype, the severity of axonal damage, and the patient's functional abilities. Coordinated work among a neurologist, rehabilitation specialist, orthopedist, and orthotist is particularly important.

Vladimir Maletskyi | 36.6 — 366 Days a Year | Physical Therapy for Genetic Disorders

Chapter 9. Hereditary Spastic Paraplegia

Part II. Hereditary Disorders of the Nervous System

Hereditary Spastic Paraplegia (HSP)

1. General Characteristics of the Disease

Hereditary spastic paraplegia is a genetically heterogeneous group of neurological disorders characterized primarily by involvement of the long motor pathways of the spinal cord and the gradual development of lower-limb spasticity.

The pathological process mainly affects the corticospinal tracts, disrupting central regulation of muscle tone and voluntary movements.

Uncomplicated (pure) and complicated forms of HSP are distinguished. The former manifest predominantly as spastic paraparesis, whereas the latter may be accompanied by additional neurological impairments.

The disease is associated with numerous genetic variants, including alterations in SPAST (SPG4), ATL1 (SPG3A), REEP1 (SPG31), and SPG7. Autosomal dominant, autosomal recessive, and X-linked inheritance patterns occur.

According to epidemiological modeling, the combined prevalence of hereditary spastic paraplegias is estimated at approximately 3.6 cases per 100,000 population. Prevalence estimates for individual subtypes, including SPG4, vary according to the population studied and the methodology used.

2. Clinical Presentation

The main manifestation of the disease is gradually increasing stiffness of the lower limbs, accompanied by increased muscle tone and difficulty walking.

Neurological examination reveals exaggerated tendon reflexes, pathological plantar responses, and varying degrees of muscle weakness.

Gait becomes stiff and slow, often with insufficient knee flexion. Marked spasticity of the hip adductor muscles may lead to a crossing, or scissoring, gait.

Patients report rapid fatigue when walking, painful muscle spasms, and difficulty turning and negotiating obstacles.

Uncomplicated forms may involve impaired vibration sensation and urinary disturbances. Complicated variants may additionally feature ataxia, peripheral neuropathy, cognitive impairment, or other neurological manifestations.

Diagnosis includes neurological examination, MRI of the brain and spinal cord to exclude other causes of spastic paraparesis, and molecular genetic testing.

3. Goals of Medical Rehabilitation

The principal goal of rehabilitation in HSP is to reduce the functional consequences of spasticity while preserving sufficient muscle activity for standing and walking.

The main objectives are:

maintaining the available range of motion in the hip, knee, and ankle joints;

preventing contractures and abnormal limb postures;

improving stability and coordination during walking;

reducing painful spasms;

preserving the ability to stand up, move independently, and perform everyday activities;

reducing the risk of falls.

When setting goals, it is important to recognize that reducing muscle tone does not always improve motor function. In some patients, increased tone partly compensates for muscle weakness and helps maintain standing.

Objective assessment uses the Modified Ashworth Scale (MAS), Spastic Paraplegia Rating Scale (SPRS), 10-Meter Walk Test, and Timed Up and Go (TUG).

4. Therapeutic Exercise

Therapeutic exercise in HSP aims to maintain joint mobility, train functional movements, and reduce the impact of spasticity on gait.

For the lower limbs, slow, controlled stretching is used for muscles prone to increased tone: the hip adductors, knee flexors, and calf muscles. Stretching is performed without jerking or painful resistance.

Exercises focusing on pelvic position control, weight shifting, and stability when changing direction are particularly important.

Gait training includes practicing step length, foot placement, and safe turning. Handrails, walkers, or partial body-weight support systems are used when necessary.

When motor function is preserved, exercises are used to strengthen the hip extensors, trunk stabilizers, and other functionally important muscle groups. Stationary cycling and graded aerobic activity may be used to maintain endurance.

The program must be adapted to the degree of spasticity and muscle weakness. Prolonged fatigue, increased spasms, or worsening gait after sessions require adjustment of the workload.

5. Massage and Device-Based Physical Therapy

Massage in HSP is considered an adjunctive method for relieving muscle discomfort and painful spasms, particularly in the calves and thighs.

Gentle techniques that do not trigger a reflex increase in muscle tone are preferred. Intensive kneading and rapid stretching of spastic muscles may provoke an undesirable motor response.

TENS may be used for selected pain syndromes. NMES or functional electrical stimulation (FES) is considered individually, particularly when ankle dorsiflexion is inadequate during walking.

Electrical stimulation does not eliminate the genetic cause of the disease; any potential benefit is assessed through changes in a specific function, such as walking safety and speed.

Therapeutic ultrasound, infrared therapy, and magnetotherapy have no proven ability to slow HSP progression. Their symptomatic use requires separate indications and assessment of clinical benefit.

6. Orthopedic and Functional Rehabilitation

The most common orthopedic problems in HSP are limited ankle dorsiflexion, shortening of the calf muscles, and the development of lower-limb contractures.