Purpose
 Forearm bathing is considered beneficial for the hands of patients with spastic hemiplegia, but the effect has not been investigated comprehensively. This study investigated the effectiveness of forearm bathing for patients with hemiplegic hands.
Subjects and Methods
 In total, nine hemiplegic patients participated in the study (mean±standard deviation age=56.9±16.6 years; mean±standard deviation period from onset=21.1±21.2 months). Participants sat in a relaxed position on a chair, and dipped the affected forearms into 40°C warm water for 15 mins. The Simple Test for Evaluating Hand Function (STEF) score was evaluated before and after forearm bathing as an indicator of hemiplegic hand function. The Modified Ashworth Scale (MAS) score for the biceps brachii muscle, and both the resistance power of elbow extension and the F/M ratio (F-wave amplitudes/ M wave amplitudes) for the abductor pollicis brevis muscle, were evaluated as indicators of hemiplegic hand spasticity. The device used to measure the resistance power of elbow extension comprised a motor, cuffs to fix the hemiplegic arm and forearm in place, and a control system. The axis of rotation of the device was positioned over the axis of rotation of the elbow joint. The device induced passive elbow flexion and extension movements at an angular velocity of 60°/sec or 90°/sec.
Results
 After forearm bathing, the STEF score increased significantly (p<0.05) from 42.9±28.0 to 47.8±28.4 (n=9), the resistance power of elbow extension at 90°/min decreased significantly (p<0.01) from 4.0±1.8 N to 3.0±1.9 N, and the MAS score and F/M ratio were unchanged (n=6).
Conclusions
 Forearm bathing appeared to improve function and decrease spasticity in hemiplegic hands. This treatment might facilitate hand rehabilitation.

 The effects of bathing in a solution of artificial bath additive including inorganic salts and carbon dioxide (CO2-bathing: 41°C, 10 minutes; the concentration of carbon dioxide was 160-180 ppm, and that of inorganic salts was about 64 ppm) on the cardiovascular system, body flexibility, muscle stiffness and the subjective feeling of bathing were compared with those of no bathing and plain water bathing in the healthy subjects.  The deep body temperature and skin blood flow increased after bathing, and the increases after CO2-bathing were significantly greater than those after plain water bathing. Body flexibility after CO2-bathing was similar to that of no bathing and plain water bathing.  Stiffness of the trapezius muscle was decreased at both 15 min and 30 min after CO2-bathing and plain water bathing, with no change in no bathing. The changes at 15 min after CO2-bathing and plain water bathing were statistically significant. Stiffness in the latissimus dorsi muscle decreased at both 15 min and 30 min after CO2-bathing and plain water bathing, with no change in no bathing. However, only these changes at 15 min and 30 min after CO2-bathing were statistically significant.  A large decrease in the stiffness of the trapezius muscle by its isometric contraction was observed during both CO2-bathing and plain water bathing, and the decrease after CO2-bathing was greater than that after plain water bathing. These changes did not reach statistical significance.  Improvements in subjective feeling of bathing were observed after both plain water bathing and CO2-bathing. Improvements after CO2-bathing in stiffness of muscle, ease of movements and mental relaxation were statistically greater than those after plain water bathing.  Compared with plain water bathing, CO2-bathing showed additional effects on muscle stiffness and subjective feeling of bathing. Further research is needed to confirm the effectiveness of the CO2-bathing alone and combined with isometric movements on muscle stiffness.