Background
Methods
Subjects
Robot device
Physical treatment
Evaluation procedures
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the Distance Index (DI) was defined as the mean distance traveled by the subject’s hand from the starting position, in percent of control values, i.e. the means of the values in healthy subjects: a maximum score of 100% indicated that the participant could reach the target (with the arm supported in the robotic device) or even pass it (hypermetria), a rare occurrence in subjects with hemiparesis. Thus, any movement exceeding the required distance was still measured as 100% in terms of Distance Index, as any excessive distance covered (hypermetria) is not counted with the InMotion™ robot.
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the Velocity Index (VE) was the hand velocity (distance traveled divided by movement time) in percent of control values;
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the Accuracy Index (AC) was the inverse of the root mean square error from straight line, in percent of control values; in other words, we computed the area under the curve of the errors between the actual trajectory of the patient’s hand and an ideal direct, linear trajectory from start to target.
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the Smoothness Index (SM) was defined in the present study as the inverse of the mean number of zero-crossings in the velocity profile, in percent of control values [41‐43]. Although there are several ways in which one may compute movement smoothness, this method, while it may be less sensitive than other methods in subjects with mild movement impairment, has been used to analyze the number of discrete (sub)movements in severely affected subjects, like the early post stroke subjects of the present study [43]. When motor recovery occurs, the velocity profile of the hand movement presents fewer peaks, resulting in a smoother movement [43]. As a potentially more sensitive metric of smoothness, we also analyzed the inverse of the mean number of zero-crossings in the acceleration profile, to verify whether patterns of changes would be similar or not between the two metrics.
Statistics
Results
Number | 22 |
---|---|
Age (years) | 53 (18) |
Gender | 9 W |
Side of hemiparesis | 12 R |
Time since stroke (days) | 63 (29) |
Etiology | I (15), H (7) |
Duration of robotic training (days) | 103 (13) |
Clinical outcomes
Fugl-Meyer | M2 (n = 19) | M3 (n = 18) | M4 (n = 17) | M5 (n = 15) | M2 vs M5 p
|
---|---|---|---|---|---|
Overall (66) | 18.0 (8.0) | 25.9 (12.1)a
| 29.3 (14.5)a
| 36.5 (12.1)a,b
| 1.6E−3
|
Shoulder/Elbow (36) | 13.1 (5.3) | 18.4 (6.8)a
| 19.3 (7.8)a
| 21.8 (6.5)a
| 5.7E−5
|
Wrist (10) | 1.3 (2.0) | 2.4 (2.6) | 2.8 (3.1) | 5.5 (5.5)a,b
| 8.5E−4
|
Hand (14) | 2.4 (2.7) | 4.4 (3.7) | 5.3 (4.7)a
| 6.2 (4.6)a
| 2.5E−3
|
Coord velocity (6) | 1.6 (1.8) | 1.5 (1.6) | 2.7 (2.0)b
| 3.0 (1.6)b
| ns |
Kinematic parameters
M2 (n = 22) | M3 (n = 22) | M4 (n = 22) | M5 (n = 22) | M2 vs M5 p
| |
---|---|---|---|---|---|
DI | 41.7(34.4) | 73.5(37.6)a
| 80.3(38.2)a
| 82.6(35.5)a
| 7.1E−8
|
VE | 37.1(28.5) | 63.5(39.4)a
| 77.9(39.4)a
| 83.4(41.7)a,b
| 3.1E-9
|
AC | 28.7(25.3) | 41.3(22.9) | 42.1(24.4) | 49.8(23.9)a
| 1.5E−3
|
SM | 41.0(24.5) | 67.0(42.6)a
| 70.0(29.4)a
| 79.3(40.2)a
| 8.3E−4
|