# Physical and Respiratory Rehabilitation in Spinal Muscular Atrophy: A Critical Narrative Review
## 3 Results
### Motor Rehabilitation
#### 3.1.3 Electrical Stimulation  
[PERSON] et al. conducted an RCT to investigate the effects of therapeutic electrical stimulation (TES; NT-2000), administered for 12 months to 13 patients with SMA II and III on the deltoid (shoulder abductor) and bicep (elbow flexor) muscles of a randomly chosen arm [48]. The opposite arm received sham stimulation (placebo), which stopped after fifteen minutes of stimulation. TES was administered using transcutaneous and conductive silicone rubber electrodes. The electric stimulator used a two-channel battery that generated pulses of coupled alternating current. It was turned on when the participant went to bed and turned off in the morning. Stimulation parameters consisted of a pulse amplitude of 300 \(\upmu\)s, a pulse frequency between 35 and 45 Hz, a peak intensity of less than 10 mA, and a 1:1 on/off cycle. The results showed no statistically significant difference between the treatment arm and the control arm at baseline, 6 and 12 months in quantitative myometry, manual muscle testing, M-wave amplitude (\(p\) = 0.12), and PEDI (\(p\) = 0.11), suggesting poor effectiveness of this treatment on SMA patients.  
[PERSON] et al. raised awareness of the potential role of electotherapy in helping improve motor performance in SMA patients [49]. The study focused on a 13-year-old adolescent with SMA type III who participated in an 18-week strengthening program divided into two phases. Phase I (weeks 1-8) involved a home-based quadriceps strengthening regimen using neuromuscular electrical stimulation (NMES). The NMES protocol was administered for 22 min per session, five days per week. It began with a 2 min warm-up phase consisting of single twitches (frequency: 5 Hz; stimulus width: 380 \(\upmu\)s), followed by a 20 min strengthening protocol featuring tetanic contractions (duration: 2 s; frequency: 35 Hz; pulse width: 380 \(\upmu\)s), interspersed with 9 s recovery periods of single twitches at 3 Hz. During phase II (weeks 9-18), NMES was combined with functional electrical stimulation (FES) and 10 sessions of voluntary cycling exercise (FES-assisted cycling). The protocol lasted 25 min and was conducted at a speed of 30 rpm, with pedal resistance progressively increasing from 5 to 9 Nm. Stimulation amplitude was set at 45 mA for the quadriceps, 30 mA for the hamstrings, and 25 mA for the gluteal muscles. Results indicated that NMES led to an increase in thigh circumference (up to 7 mm by the end of Phase I), suggesting muscle mass gain. Functionally, improvements were observed on the HFMSE scale, particularly in items related to standing performance and lower limb motor abilities. Similarly, the Tinetti scale allowed appreciation of a substantial gain in balance and gait.  
[PERSON] et al. investigated the effects of transcutaneous spinal cord stimulation combined with physical therapy in five children with genetically confirmed SMA II or III [57]. Participants, classified as sitters or non-sitters, had been receiving nusinersen for approximately two years. The intervention aimed to reduce joint contractures, improve endurance, and develop motor skills through individualised rehabilitation plans. Sessions included passive and active stretching, weight-bearing exercises, stepping movements, and breathing exercises, supplemented by additional therapies such as massage. Functionalimprovements were observed in four participants, including increased independent sitting time, improved transfers, and enhanced posture control. No adverse events were reported, and participants tolerated the intervention well.