Table 1
Baseline data of 42 patients with post-stroke upper limb spasticity
| Clinical characteristics | Value/number | Percentage (%) |
|---|---|---|
| Age (years) | 52.45 ± 8.76 | — |
| Sex (male/female) | 24/18 | 57.14/42.86 |
| Disease duration (months) | 3.28 ± 1.45 | — |
| Ischemic stroke | 28 | 66.67 |
| Hemorrhagic stroke | 14 | 33.33 |
| MAS grade I | 12 | 28.57 |
| MAS grade II | 18 | 42.86 |
| MAS grade III | 12 | 28.57 |
Table 2
Comparison of electromyographic amplitude parameters of various muscles between patients and normal participants at rest
| Group | Anterior forearm flexor muscles (RMS/iEMG) | Posterior forearm extensor muscles | ||||||
|---|---|---|---|---|---|---|---|---|
| Flexor pollicis longus | Flexor digitorum superficialis | Flexor carpi ulnaris | Flexor carpi radialis | Pronator teres | Extensor digitorum | Extensor carpi radialis | Extensor pollicis longus | |
| Affected side | 47.1/37.1 | 45.6/35.9 | 40.0/31.0 | 33.2/25.8 | 36.5/28.4 | 41.7/33.1 | 26.4/20.3 | 24.8/19.1 |
| Unaffected side | 8.6/6.7 | 8.7/6.9 | 9.3/7.3 | 8.8/6.9 | 8.5/6.6 | 10.8/8.6 | 18.0/12.6 | 15.3/11.8 |
| Healthy control | 12.5/9.6 | 8.7/6.5 | 5.8/4.6 | 5.7/4.6 | 6.4/5.1 | 9.3/7.4 | 6.2/5.0 | 5.6/4.5 |
Note: RMS is expressed in μV, and iEMG is expressed in μV s.
Table 3
Comparison of sEMG parameters of forearm muscles during active movement
| Group | Anterior forearm flexor muscles (RMS/iEMG) | Posterior forearm extensor muscles | ||||||
|---|---|---|---|---|---|---|---|---|
| Flexor pollicis longus | Flexor digitorum superficialis | Flexor carpi ulnaris | Flexor carpi radialis | Pronator teres | Extensor digitorum | Extensor carpi radialis | Extensor pollicis longus | |
| Affected side | 123.1/93.0 | 117.9/88.9 | 79.5/60.2 | 74.5/57.7 | 82.6/63.1 | 68.1/53.3 | 128.7/99.8 | 58.4/45.6 |
| Unaffected side | 180.1/133.2 | 184.4/134.2 | 202.5/148.0 | 160.3/118.6 | 175.8/129.5 | 111.7/78.6 | 177.2/126.8 | 98.5/72.8 |
| Healthy control | 318.8/220.6 | 375.2/245.0 | 464.1/325.7 | 254.9/182.2 | 287.3/201.5 | 193.8/140.6 | 269.5/180.9 | 178.6/128.3 |
Note: RMS is expressed in μV, and iEMG is expressed in μV s.
Figure 1
Comparison of MSS scores in enrolled patients before and after treatment.
Figure 2
Correlation analysis between trajectory length and EMG parameters. The trajectory length was negatively correlated with iEMG (a), RMS (b), MF (c), and MPF (d) (P < 0.05). Note: Neuromuscular function is represented by the mean values of iEMG, RMS, MF, and MPF derived from the flexor pollicis longus, flexor digitorum superficialis, flexor carpi ulnaris, flexor carpi radialis, and pronator teres.
Figure 3
Correlation analysis between envelope area and EMG parameters. The envelope area was negatively correlated with iEMG (a), RMS (b), MF (c), and MPF (d) (P < 0.05).
Table 4
Correlation analysis between sEMG signals and balance function parameters
| iEMG | RMS | MF | MPF | |
|---|---|---|---|---|
| Trajectory length | r = −0.567 | r = −0.107 | r = −0.069 | r = −0.109 |
| P < 0.0001 | P = 0.035 | P = 0.046 | P = 0.032 | |
| Envelope area | r = −0.583 | r = −0.107 | r = −0.085 | r = -0.108 |
| P < 0.0001 | P = 0.034 | P = 0.049 | P = 0.033 |
Figure 4
ROC curve analysis of EMG parameters for evaluating upper limb spasticity recovery. The AUCs for iEMG, RMS, MF, and MPF were 0.748, 0.731, 0.737, and 0.826, respectively (P < 0.05).
| Muscle | Electrode location | Orientation and inter-electrode distance |
|---|---|---|
| Flexor pollicis longus | Volar aspect of the forearm, approximately 4 cm proximal to the radial styloid process, at the point of greatest muscle bulge | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Flexor digitorum superficialis | Middle volar forearm, between the flexor carpi ulnaris and flexor carpi radialis | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Flexor carpi ulnaris | Ulnar side of the forearm, approximately 2 cm distal to the medial epicondyle of the ulna | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Flexor carpi radialis | Radial side of the volar forearm, 3 cm distal to the medial epicondyle of the humerus | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Pronator teres | Volar aspect of the forearm, at the proximal one-third point of the line between the medial epicondyle and the midpoint of the radius | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Extensor digitorum | Volar aspect of the forearm, approximately 3 cm distal to the lateral epicondyle of the humerus | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Extensor carpi radialis | Radial side of the dorsal forearm, approximately 2 cm distal to the lateral epicondyle of the humerus | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Extensor pollicis longus | Ulnar side of the dorsal forearm, approximately 4 cm proximal to the radial styloid process | Along the direction of muscle fibers; inter-electrode distance: 20 mm |
| Reference electrode: The reference electrode was placed over the olecranon of the ulna on the ipsilateral side (bony landmark) | ||
Note: All electrodes were bipolar surface electrodes with an inter-electrode distance of 20 mm. The reference electrode was placed over the ipsilateral olecranon of the ulna. For skin preparation, the area was cleaned with 75% ethanol, and the electrodes were attached after the skin had dried.
| Dimension (scores) | No. of items | Main assessment movement |
|---|---|---|
| Shoulder movement (20 points) | 8 | Active movements including shoulder abduction, flexion, extension, internal/external rotation, etc. |
| Elbow and forearm movement (18 points) | 6 | Elbow flexion and extension, forearm pronation and supination, etc. |
| Wrist movement (14 points) | 5 | Wrist dorsiflexion, palmar flexion, radial and ulnar deviation, etc. |
| Hand movement (20 points) | 7 | Fine motor tasks such as thumb opposition, lateral pinching, tripod pinching, and gross grasp |
| Upper limb movement based on hand function (10 points) | 3 | Functional tasks such as combing hair, turning door knobs and opening doors, and drinking from cups |
Note: Each item is scored on a 6-point scale (0–5), where 0 indicates inability to perform the task and 5 indicates normal performance.