**3. Characteristics of the H-reflex and F-wave in different stretched arm positions in the CVD patients**

#### **3.1. The effects of continuous stretching of the affected arm (the H-reflex study)**

Neurological findings, including muscle tonus and tendon reflex, were also evaluated. Findings of muscle tonus and tendon reflex were classified into increased (markedly, moder‐

The results were analyzed in terms of the characteristic appearance of the H-reflex and F-wave in the healthy subjects and the relationship between the neurological findings of CVD and the

H-reflex and F-wave patterns resulting from increased stimulus intensity were type 1 in all healthy subjects. The relationship between H-reflex and F-wave patterns resulting from increased stimulus intensity and the neurological signs of CVD is shown in Tables 1 and 2. Hreflex and F-wave patterns resulting from increased stimulus intensity in patients with markedly increased muscle tonus and tendon reflex were most frequently type 4 patterns, those in patients with moderately increased muscle tonus and tendon reflex were type 2 or 3 patterns, those in patients with slightly increased muscle tonus and tendon reflex were type 1 or 2 patterns, and those in patients with normal or decreased muscle tonus and tendon reflex

**Increased Normal Decreased**

**Increased Normal Decreased**

characteristic appearance of the H-reflex and F-wave in the CVD patients.

**Markedly Moderately Slightly**

The number of subjects was 31 (Type 1: 10, Type 2: 8, Type 3: 7, Type 4: 6)

The number of subjects was 31(Type 1: 10, Type 2: 8, Type 3: 7, Type 4: 6)

Type 1 0 0 2 5 3 Type 2 0 4 4 0 0 Type 3 2 4 1 0 0 Type 4 5 1 0 0 0

**Table 1.** The relationship between H-reflex and F-wave patterns resulting from increased stimulus intensity and

Type 1 0 0 1 6 3 Type 2 0 3 5 0 0 Type 3 2 4 1 0 0 Type 4 4 2 0 0 0

**Table 2.** The relationship between H-reflex and F-wave patterns resulting from increased stimulus intensity and

**Markedly Moderately Slightly**

ately, and slightly), normal, and decreased.

30 Electrodiagnosis in New Frontiers of Clinical Research

were type 1 patterns.

muscle tonus

tendon reflex

Ten hemiplegic patients (4 male and 6 female) with hypertonus caused by CVD were tested. The mean patient age was 53.2 years (range: 34–63 years). There were 5 patients with cerebral hemorrhage (2 with right and 3 with left hemiplegia) and 5 with cerebral infarction (2 with right and 3 with left hemiplegia). The cortical location of the lesion, as verified by brain computed tomography, was temporal in 4 patients, parietal in 2, and temporo-occipital in 2. The lesion was located in the brain stem in the remaining 2 patients. Patients were divided into 3 groups on the basis of the extent of increase in muscle tonus: one group with slightly increased muscle tonus (2 patients), one with moderately increased muscle tonus (6 patients), and one with markedly increased muscle tonus (2 patients).

The H-reflexes before, during, and 0, 2, 4, 6, 8, and 10 min after continuous stretching of the abductor pollicis brevis (APB) muscle of the affected side were recorded following stimulation of the median nerve at the wrist. The intensity of the constant stimulation current was 1.2 times greater than that of the minimum current required to evoke an M-wave with a stimulus frequency of 0.5 Hz and duration of 0.2 ms. Stimulation was performed 30 times in each trial. The H-reflex was analyzed for persistence, amplitude ratio of H/M, and latency, which was determined as the mean of measurable H-reflexes. Stretching comprised continuous stretching of the affected arm with shoulder joint abduction, elbow joint extension, wrist joint dorsiflex‐ ion, and finger extension for 1 min (Fig 6). Using this data, we analyzed H-reflex characteristics resulting from continuous stretching of the affected arm as well as the relationship between the effects of continuous stretching and neurological findings in the CVD patients.

Persistence and amplitude ratio of H/M were significantly lower (p < 0.05) after stretching than before stretching; these characteristics gradually recovered after continuous stretching. Figure 7 shows the amplitude ratio of H/M before, during, and after continuous stretching. A typical H-reflex is shown in Figure 8. There was no significant difference in latency. Persistence and amplitude ratio of H/M during continuous stretching were lower than those before and after stretching in the patients with moderately increased muscle tonus. The amplitude ratio of H/ M before, during, and after continuous stretching in patients with moderately increased muscle tonus is shown in Figure 9. On the other hand, H-reflex characteristics were the same before, during, and after continuous stretching in the patients with slightly or markedly increased muscle tonus (Fig 10). Latency was the same before, during, and after continuous stretching in all patients, irrespective of slightly, moderately, or markedly increased muscle tonus.

tonus. **Figure 6.** Continuous stretching of the affected arm with shoulder joint abduction, elbow joint extension, wrist joint dorsiflexion, and finger extension for 1 min

Fig 8. A typical H-reflex pattern before, during, and after continuous stretching (Left

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**Figure 8.** A typical H-reflex pattern before, during, and after continuous stretching (Left hemiplegia, 59-year-old male) The amplitude of the H-reflex during and after stretching was lower than that before stretching. The amplitude gain

> The amplitude of the H-reflex during and after stretching was lower than that before stretching. The amplitude gain was 5 mV (M wave) and 1 mV (H-reflex). Gain of

Before During After 0 After 2 After 4 After 6 After 8 After 10 Recording time (min)

**Figure 9.** Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with moderately increased muscle tonus The amplitude ratio of H/M during stretching was lower, while that after

Fig 9. Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with moderately increased muscle tonus

The amplitude ratio of H/M during stretching was lower, while that after stretching

hemiplegia, 59-year-old male)

was 5 mV (M wave) and 1 mV (H-reflex). Gain of latency was 5 ms.

Before

During

After

latency was 5 ms.

0

gradually increased.

stretching gradually increased.

10

20

30

Amplitude ratio of H/M (%)

40

50

60

Figure 7. Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching The amplitude ratio of H/M during (p < 0.05) and after stretching was lower than that before stretching, and it gradually increased after stretching. **Figure 7.** Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching The amplitude ratio of H/M during (p < 0.05) and after stretching was lower than that before stretching, and it gradually increased after stretching.

Figure 8. A typical H-reflex pattern before, during, and after continuous stretching (Left hemiplegia, 59-year-old male) The amplitude of the Hreflex during and after stretching was lower than that before stretching. The amplitude gain was 5 mV (M wave) and 1 mV (H-reflex). Gain of

latency was 5 ms.

Persistence and amplitude ratio of H/M were significantly lower (p < 0.05) after stretching than before stretching; these characteristics gradually recovered after continuous stretching. Figure 7 shows the amplitude ratio of H/M before, during, and after continuous stretching. A typical H-reflex is shown in Figure 8. There was no significant difference in latency. Persistence and amplitude ratio of H/M during continuous stretching were lower than those before and after stretching in the patients with moderately increased muscle tonus. The amplitude ratio of H/M before, during, and after continuous stretching in patients with moderately increased muscle tonus is shown in Figure 9. On the other hand, H-reflex characteristics were the same before, during, and after continuous stretching in the patients with slightly or markedly increased muscle tonus (Fig 10). Latency was the same before, during, and after continuous stretching in all patients, irrespective of slightly, moderately, or markedly increased muscle

Figure 7. Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching The amplitude ratio of H/M during (p < 0.05)

Figure 8. A typical H-reflex pattern before, during, and after continuous stretching (Left hemiplegia, 59-year-old male) The amplitude of the Hreflex during and after stretching was lower than that before stretching. The amplitude gain was 5 mV (M wave) and 1 mV (H-reflex). Gain of

and after stretching was lower than that before stretching, and it gradually increased after stretching.

**Figure 7.** Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching The amplitude ratio of H/M during (p < 0.05) and after stretching was lower than that before stretching, and it gradually increased

**Figure 6.** Continuous stretching of the affected arm with shoulder joint abduction, elbow joint extension, wrist joint

Before During After 0 After 2 After 4 After 6 After 8 After 10 Recording time (min)

tonus.

0

after stretching.

5

10

Amplitude ratio of H/M (%)

15

20

25

dorsiflexion, and finger extension for 1 min

32 Electrodiagnosis in New Frontiers of Clinical Research

latency was 5 ms.

Fig 8. A typical H-reflex pattern before, during, and after continuous stretching (Left hemiplegia, 59-year-old male) **Figure 8.** A typical H-reflex pattern before, during, and after continuous stretching (Left hemiplegia, 59-year-old male) The amplitude of the H-reflex during and after stretching was lower than that before stretching. The amplitude gain was 5 mV (M wave) and 1 mV (H-reflex). Gain of latency was 5 ms.

The amplitude of the H-reflex during and after stretching was lower than that before

Fig 9. Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with moderately increased muscle tonus **Figure 9.** Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with moderately increased muscle tonus The amplitude ratio of H/M during stretching was lower, while that after stretching gradually increased.

The amplitude ratio of H/M during stretching was lower, while that after stretching

gradually increased.

influence excitability of spinal neural function. The last difference concerns the method used. We speculate that differences in the method of muscle stretching also affect the excitability of spinal neural function. Clinically, continuous stretching of the arm involves the simultaneous stretching of several joints, particularly according to the Bobath concept. Therefore, the affected muscle tonus is changed by muscle contraction and muscle stretching in remote parts of the

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Patients with moderately increased muscle tonus were more affected by these stretch condi‐ tions in our study. Excitability of spinal neural function during 1 min of continuous stretching was inhibited in the patients with moderately increased muscle tonus, whereas that in the patients with slightly or markedly increased muscle tonus was less affected. Therefore, it is important to examine neurological findings using continuous stretching as one of the rehabil‐

**3.2. F-wave characteristics in different stretched positions of the affected arm in CVD**

The subjects were 20 hemiparesis patients with moderate hypertonus (modified Ashworth scale score of 2 or 3) caused by CVD. Their mean age was 49.5 years. There were 10 patients with cerebral hemorrhage (5 with right and 5 with left) and 10 with cerebral infarction (5 with right and 5 with left). Computed tomography or magnetic resonance imaging confirmed the cortical lesions to be located in the temporal region in 5 patients, parietal region in 3, temporooccipital region in 3, and brain stem in 5. The muscle tonus of the affected arm, especially the distal part, was moderately increased according to a modified Ashworth scale score of 2 or 3. The F-wave was recorded at the APB during continuous stretching for 1 min after stimulation of the median nerve at the wrist. The first trial was a relaxation trial, followed by continuous stretching of the affected arm for 1 min in the following positions: stretched position with shoulder joint abduction (trial 2, Fig 11), stretched position with shoulder joint abduction and elbow joint extension (trial 3, Fig 12), and stretched position with shoulder joint abduction, elbow joint extension, and wrist joint extension (trial 4, Fig 6). The intensity of the constant stimulation current was 1.2 times greater than that of the minimum current required to evoke a maximal M-wave with a stimulus frequency of 0.5 Hz and duration of 0.2 ms. Stimulation was performed 30 times in each trial. The F-wave was analyzed for persistence, amplitude ratio of F/M, and latency, which were the mean values of the measurable F-waves. Using this data, F-wave characteristics during continuous stretching (trials 2–4) were compared with those during relaxation (trial 1) in the CVD patients with moderately increased muscle

The following results were analyzed: 1) relationship between F-wave characteristics in trial 1 and trial 2, 2) relationship between F-wave characteristics in trial 1 and trial 3, and 3) relation‐

With regard to the relationship between F-wave characteristics in trial 1 and trial 2, persistence,

ship between F-wave characteristics in trial 1 and trial 4.

amplitude ratio of F/M, and latency were the same in trial 1 and 2.

body.

itation treatments.

**patients**

hypertonus.

Fig 10. Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with slightly and markedly increased muscle tonus **Figure 10.** Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with slightly and markedly increased muscle tonus The figure shows typical data in patients with slightly (dash line) and markedly (solid line) increased muscle tonus. The amplitude ratio of H/M before, during, and after stretching re‐ mained the same.

The figure shows typical data in patients with slightly (dash line) and markedly (solid line) increased muscle tonus. The amplitude ratio of H/M before, during, and after stretching remained the same. Generally, the H-reflex is suppressed during passive stretching in healthy subjects, although the mechanism has not been clarified. Depression was thought to be caused by a decrease in the number of afferent fibers fired from the Golgi tendon organs and muscle spindle during passive stretching (Paillard, 1959 and Mark et al., 1968). The increase in the H-reflex following passive stretching, caused by excitability of cortical and spinal neural function, was greater in spastic patients than in healthy subjects (Angel et al., 1963, Niesen et al., 1993, and Hashizume et al., 1985). However, our results demonstrate that H-reflexes during 1 min of continuous stretching of the affected arm were significantly decreased compared with those before continuous stretching, especially in the CVD patients with moderately increased muscle tonus. There are 3 differences between the results of other studies and our results. First is the duration of stretching, which was considerably shorter (1 min) in our study than in the other studies. It is well known that in healthy subjects, excitability of spinal neural function during continuous stretching is decreased because of the inhibitory neurons from the Ib afferents. These Ib afferents from the Golgi tendon organs, which fire in response to muscle tension, are reportedly influenced by corticospinal fibers (Lundberg et al., 1978). Excitability of spinal neural function during muscle stretching showed a greater increase in the spastic CVD patients than in the healthy subjects because Ib afferent inhibitory neurons are not fired under short stretching durations. Therefore, CVD patients require longer durations of continuous stretching of the affected hypertonic muscle to fire the Ib inhibitory neurons. The second difference lies in the stretched muscle. In the other studies, affected calf muscles were stretched, whereas in our study, the arm muscles were stretched. Therefore, differences in stretched muscle also influence excitability of spinal neural function. The last difference concerns the method used. We speculate that differences in the method of muscle stretching also affect the excitability of spinal neural function. Clinically, continuous stretching of the arm involves the simultaneous stretching of several joints, particularly according to the Bobath concept. Therefore, the affected muscle tonus is changed by muscle contraction and muscle stretching in remote parts of the body.

Patients with moderately increased muscle tonus were more affected by these stretch condi‐ tions in our study. Excitability of spinal neural function during 1 min of continuous stretching was inhibited in the patients with moderately increased muscle tonus, whereas that in the patients with slightly or markedly increased muscle tonus was less affected. Therefore, it is important to examine neurological findings using continuous stretching as one of the rehabil‐ itation treatments.

## **3.2. F-wave characteristics in different stretched positions of the affected arm in CVD patients**

mained the same.

stretching remained the same.

Amplitude ratio of H/M (%)

34 Electrodiagnosis in New Frontiers of Clinical Research

Before During After 0 After 2 After 4 After 6 After 8 After 10 Recording time (min)

**Figure 10.** Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with slightly and markedly increased muscle tonus The figure shows typical data in patients with slightly (dash line) and markedly (solid line) increased muscle tonus. The amplitude ratio of H/M before, during, and after stretching re‐

Generally, the H-reflex is suppressed during passive stretching in healthy subjects, although the mechanism has not been clarified. Depression was thought to be caused by a decrease in the number of afferent fibers fired from the Golgi tendon organs and muscle spindle during passive stretching (Paillard, 1959 and Mark et al., 1968). The increase in the H-reflex following passive stretching, caused by excitability of cortical and spinal neural function, was greater in spastic patients than in healthy subjects (Angel et al., 1963, Niesen et al., 1993, and Hashizume et al., 1985). However, our results demonstrate that H-reflexes during 1 min of continuous stretching of the affected arm were significantly decreased compared with those before continuous stretching, especially in the CVD patients with moderately increased muscle tonus. There are 3 differences between the results of other studies and our results. First is the duration of stretching, which was considerably shorter (1 min) in our study than in the other studies. It is well known that in healthy subjects, excitability of spinal neural function during continuous stretching is decreased because of the inhibitory neurons from the Ib afferents. These Ib afferents from the Golgi tendon organs, which fire in response to muscle tension, are reportedly influenced by corticospinal fibers (Lundberg et al., 1978). Excitability of spinal neural function during muscle stretching showed a greater increase in the spastic CVD patients than in the healthy subjects because Ib afferent inhibitory neurons are not fired under short stretching durations. Therefore, CVD patients require longer durations of continuous stretching of the affected hypertonic muscle to fire the Ib inhibitory neurons. The second difference lies in the stretched muscle. In the other studies, affected calf muscles were stretched, whereas in our study, the arm muscles were stretched. Therefore, differences in stretched muscle also

Fig 10. Characteristics of the amplitude ratio of H/M before, during, and after continuous stretching in patients with slightly and markedly increased muscle tonus

The figure shows typical data in patients with slightly (dash line) and markedly (solid line) increased muscle tonus. The amplitude ratio of H/M before, during, and after

The subjects were 20 hemiparesis patients with moderate hypertonus (modified Ashworth scale score of 2 or 3) caused by CVD. Their mean age was 49.5 years. There were 10 patients with cerebral hemorrhage (5 with right and 5 with left) and 10 with cerebral infarction (5 with right and 5 with left). Computed tomography or magnetic resonance imaging confirmed the cortical lesions to be located in the temporal region in 5 patients, parietal region in 3, temporooccipital region in 3, and brain stem in 5. The muscle tonus of the affected arm, especially the distal part, was moderately increased according to a modified Ashworth scale score of 2 or 3. The F-wave was recorded at the APB during continuous stretching for 1 min after stimulation of the median nerve at the wrist. The first trial was a relaxation trial, followed by continuous stretching of the affected arm for 1 min in the following positions: stretched position with shoulder joint abduction (trial 2, Fig 11), stretched position with shoulder joint abduction and elbow joint extension (trial 3, Fig 12), and stretched position with shoulder joint abduction, elbow joint extension, and wrist joint extension (trial 4, Fig 6). The intensity of the constant stimulation current was 1.2 times greater than that of the minimum current required to evoke a maximal M-wave with a stimulus frequency of 0.5 Hz and duration of 0.2 ms. Stimulation was performed 30 times in each trial. The F-wave was analyzed for persistence, amplitude ratio of F/M, and latency, which were the mean values of the measurable F-waves. Using this data, F-wave characteristics during continuous stretching (trials 2–4) were compared with those during relaxation (trial 1) in the CVD patients with moderately increased muscle hypertonus.

The following results were analyzed: 1) relationship between F-wave characteristics in trial 1 and trial 2, 2) relationship between F-wave characteristics in trial 1 and trial 3, and 3) relation‐ ship between F-wave characteristics in trial 1 and trial 4.

With regard to the relationship between F-wave characteristics in trial 1 and trial 2, persistence, amplitude ratio of F/M, and latency were the same in trial 1 and 2.

**Figure 12.** Continuous stretching of the affected arm with shoulder joint abduction and elbow joint extension

With regard to the relationship between F-wave characteristics in trial 1 and trial 3, persistence and amplitude ratio of F/M were significantly lower in trial 3 than in trial 1 (p < 0.05; Table 3

**trial 1 trial 3 t-test**

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and Fig 13). No significant difference was noticed in latency between trials 1 and 3.

Persistence (%) 100 ± 0.00 91.0 ± 41.8 p < 0.05 Amplitude ratio of F/M (%) 10.8 ± 3.5 2.71 ± 3.53 p < 0.05 Latency (ms) 25.3 ± 2.28 25.6 ± 3.17 NS

Persistence and amplitude ratio of F/M in trial 3 were significantly lower than those in trial 1.

for 1 min

NS: Not Significant

**Table 3.** F-wave characteristics in trials 1 and 3

**Figure 11.** Continuous stretching of the affected arm with shoulder joint abduction for 1 min

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**Figure 12.** Continuous stretching of the affected arm with shoulder joint abduction and elbow joint extension for 1 min

With regard to the relationship between F-wave characteristics in trial 1 and trial 3, persistence and amplitude ratio of F/M were significantly lower in trial 3 than in trial 1 (p < 0.05; Table 3 and Fig 13). No significant difference was noticed in latency between trials 1 and 3.


NS: Not Significant

**Figure 11.** Continuous stretching of the affected arm with shoulder joint abduction for 1 min

36 Electrodiagnosis in New Frontiers of Clinical Research

Persistence and amplitude ratio of F/M in trial 3 were significantly lower than those in trial 1.

**Table 3.** F-wave characteristics in trials 1 and 3

Trial 1

Trial 4

decreased the excitability of spinal neural function.

joints or all the shoulder, elbow, and wrist joints.

and F-wave.

caused by CVD.

**Figure 14.** A typical F-wave in trials 1 and 4 The F-wave amplitude in trial 4 was significantly lower than that in trial 1. The amplitude gain was 5 mV/D (M-wave) and 2 mV/D (F-wave). The latency gain was 5 ms/D for both the M-wave

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Furthermore, persistence and amplitude ratio of F/M of F-waves generated by the APB were significantly lower during 1 min of stretching in all positions than during relaxation (no stretched position) in the CVD patients with moderate hypertonus. All stretching positions

The method of stretching the affected arm involved the simultaneous stretching of several muscles rather than just one muscle. The period of continuous stretching in our study was

Continuous stretching of the proximal shoulder and elbow of the affected arm is believed to decrease excitability of spinal neural function due to Ib inhibitory neuron afferents (Mark et al., 1968) and central nervous function (Staines WR et al., 1997). We hypothesize that decreasing excitability of proximal spinal and central neural function can decrease excitability of distal spinal neural function in patients with hemiparesis accompanied by moderate hypertonus

Our study suggests that excitability of distal spinal neural function in the APB of the affected arm decreases during continuous stretching of the proximal muscle and shoulder and elbow

shorter (1 min) than that in the other studies (10 min, 30 min; Odeen, 1981).

**Figure 13.** A typical F-wave in trial 1 and 3 Amplitude of the F-wave in trial 3 was significantly lower than that in trial 1. The amplitude gain was 5 mV/D (M-wave) and 2 mV/D (F-wave). The latency gain was 5 ms/D for both the M-wave and F-wave.

With regard to the relationship between F-wave characteristics in trial 1 and trial 4, persistence and amplitude ratio of F/M were significantly lower in trial 4 than in trial 1 (p < 0.05; Table 4 and Fig 14). No significant difference was noticed in latency between trials 1 and 4.


NS: Not Significant

Persistence and amplitude ratio of F/M in trial 4 were significantly lower than those in trial 1.

**Table 4.** F-wave characteristics in trials 1 and 4

Trial 1

38 Electrodiagnosis in New Frontiers of Clinical Research

Trial 3

and F-wave.

NS: Not Significant

**Table 4.** F-wave characteristics in trials 1 and 4

**Figure 13.** A typical F-wave in trial 1 and 3 Amplitude of the F-wave in trial 3 was significantly lower than that in trial 1. The amplitude gain was 5 mV/D (M-wave) and 2 mV/D (F-wave). The latency gain was 5 ms/D for both the M-wave

With regard to the relationship between F-wave characteristics in trial 1 and trial 4, persistence and amplitude ratio of F/M were significantly lower in trial 4 than in trial 1 (p < 0.05; Table 4

**trial 1 trial 4 t-test**

and Fig 14). No significant difference was noticed in latency between trials 1 and 4.

Persistence (%) 100 ± 0.00 82.5 ± 21.8 p < 0.05 Amplitude ratio of F/M (%) 7.34 ± 3.5 4.26 ± 3.78 p < 0.05 Latency (ms) 24.5 ± 2.58 24.5 ± 2.58 NS

Persistence and amplitude ratio of F/M in trial 4 were significantly lower than those in trial 1.

**Figure 14.** A typical F-wave in trials 1 and 4 The F-wave amplitude in trial 4 was significantly lower than that in trial 1. The amplitude gain was 5 mV/D (M-wave) and 2 mV/D (F-wave). The latency gain was 5 ms/D for both the M-wave and F-wave.

Furthermore, persistence and amplitude ratio of F/M of F-waves generated by the APB were significantly lower during 1 min of stretching in all positions than during relaxation (no stretched position) in the CVD patients with moderate hypertonus. All stretching positions decreased the excitability of spinal neural function.

The method of stretching the affected arm involved the simultaneous stretching of several muscles rather than just one muscle. The period of continuous stretching in our study was shorter (1 min) than that in the other studies (10 min, 30 min; Odeen, 1981).

Continuous stretching of the proximal shoulder and elbow of the affected arm is believed to decrease excitability of spinal neural function due to Ib inhibitory neuron afferents (Mark et al., 1968) and central nervous function (Staines WR et al., 1997). We hypothesize that decreasing excitability of proximal spinal and central neural function can decrease excitability of distal spinal neural function in patients with hemiparesis accompanied by moderate hypertonus caused by CVD.

Our study suggests that excitability of distal spinal neural function in the APB of the affected arm decreases during continuous stretching of the proximal muscle and shoulder and elbow joints or all the shoulder, elbow, and wrist joints.
