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Follow-up report on the electrically driven hand splint
Follow-up report on the electrically driven hand splint Since the electrically driven hand splint was introduced in 1972, significant improvements have been made in the design and fabrication of the unit which have made it safer, easier to apply, and readily adjustable to the range of motion of a given finger. Over the last 12 months the results of this form of passive exercise were studied by comparing the gain in total active and passive motion in stiff fingers exercised over a 1 month period with similar stiff fingers treated by conventional manual passive joint exercise. There was a significant improvement in the mean gain of both total active and passive motion in those fingers treated with the electrically driven splint.
Lynn D. Ketchum, M.D., Ann Hibbard, O.T.R., and Khatab M. Hassanein, Ph.D., Overland Park, Kan.
The electrically driven hand splint (Figs lA, IB, and
IC) was introduced in 1972. Although it was originally designed during the Vietnamese conflict to passively move repaired tendons during the 7 to 8 hours of sleep each day, it has not been used for that purpose to date. Instead, it has been used exclusively to prevent or overcome stiff joints by providing continuous, gentle, reciprocal passive motion. The crude-looking prototype model did accomplish this job. Joint contractures that were resistant to previous efforts of dynamic splinting responded to the electrically driven splint. Use of the machine made it possible to exercise the three joints of each finger (the thumb is not included) in one-fourth of the time it took a therapist and did it as gently, yet more consistently. The extra time allowed the therapist to tend to other aspects of patient care, e.g., splint fabrication, program planning, documentation of progress, etc., or to treatment of another patient. Since 1972 significant improvements have been made in this exercise machine which are diagrammatically depicted in Fig. 2. * The unit is more compact and durable (Fig. 3); it is safer in that it has an easy shut-off control that the patient can use, and Underwriter's Laboratories has approved it as being safe from electrical shock. The unit is easy to set up. The patients quickly learn how to install it for an exercise period
Received for publication March 8, 1979. Reprint requests: Lynn D. Ketchum, M.D., 10550 Quivira Rd., Suite 310, Overland Park, KS 66215.
*Although the concepts of the improvements made were those of the authors, the design and fabrication were made by the engineering department of the Burnett Instrument Co., Lawrence, Kansas.
474
THE JOURNAL OF HAND SURGERY
(Fig. 4). To date eight patients have taken the unit home for a week at a time for daily use. One of the significant improvements is that the range of motion for each finger can be adjusted individually with ease (Fig. 5); this permits each finger to move through a greater or lesser range of motion than any other finger while they are all moving simultaneously. Finally, materials have been used to make the unit light and mobile and to permit the hand to be exercised while in an elevated position. We have evaluated the results of the use of the electrically driven hand splint over the past year and have compared them to those in which stiff joints were passively exercised manually.
Materials and methods Four hundred and twenty-six joints in 142 fingers were studied. They were divided into the following groups: Group I. Short term- 74 fingers: all of the fingers in this group were passively exercised in the electrically driven splint for thirty minutes and the mean gain in total active and passive motion determined. Group II. Forty-three fingers: in this group each finger was passively exercised by the electrically driven splint for 30 minutes twice a week for 4 weeks and the following determinations were made: (1) the mean gain in total active and passive motion per session; and (2) the mean gain in total active and passive motion from the beginning to the end of the month. Group III. Twenty-five fingers: these were the control fingers which were each passively exercised manually by a therapist for 30 minutes twice a week for 4
0363-5023/79/040474+08$00.80/0 © 1979 American Society for Surgery of the Hand
Vol. 4, No.5 September, 1979
Electrically driven hand splint
Fig. lAo The reciprocating mechanism of the motor in which there are two sets of cables going to the fingers: one to the dorsum of the finger and one to the volar side of the finger.
Figs. IB and IC. B, The cables on the dorsal side of the finger have shortened, extending the finger. C, The cables on the volar side of the finger have shortened, flexing the fingers into the palm. Thimbles are used to attach the fingers to the mechanism.
475
476
The Journal of HAND SURGERY
Ketchum, Hibbard. Hassanein
HAND SUPPORT PlATE
FlEXION TAt--~/ DR lYE A M - - - J
LEY DRIVE CORD EXTEHSION TAB
Fig. 2. The device is motor-driven through extension and flexion modes at the rate of 2 cpm. The force of the motor is transmitted through a hidden drive chain to the drum. Mounted on the circumference of the drum are four rings which are driven by drive arms mounted directly on the surface of the drum. The rings have two adjustable tabs that can be moved along the circumference of the ring . The position of these tabs directly relates to the location of the trolleys riding on the curved plastic trolley support. Calibration marks assist in locating the tabs in reference to the desired operating range of the trolleys. Each trolley may be custom set to operate within the tolerance range determined by the therapist.
weeks with the same determinations being made as for Group II. A total of 3,514 measurements were made. Results
The mean short term gains in total active and passive motion for fingers passively exercised by the electrically driven hand splint (group I) are seen in Table I. The mean gain in total active motion was 21.8° ± 11.8°. The mean gain in total passive motion was 19.0° ± 14.9°. Although there was no significant difference statistically between the means for active and passive motion, by the use of Student's paired t-test, there was a significant difference (P < 0.01) between active and passive motion for the amount of motion after therapy as compared with measurements before therapy .
In Table II the mean gain in total active and passive motion per exercise session over a I month period is seen for groups II and III. The mean gain in total active motion for all fingers exercised by the electrically driven splint (EDS) was 17.8° ± 9.4° for group II and 12.7° ± 6.00 for group III, manually exercised. The mean gain in total passive motion for the EDS group was 18.5° ± 7.3° and 14.0° ± 4.9° for the manually exercised group. Again, although there was no significant difference statistically between the two methods per exercise period, by use of Student's paired t-test there was a significant difference (P < 0.01) between both methods regarding both active and passive motion prior to the exercise sessions as compared with the mean measurements after the exercise session. In Table III the mean gain in total active and passive
Vol. 4 , No.5 September, 1979
Electrically driven hand splint
477
Fig. 3. The updated unit, which is more compact. Again, the fingers are reciprocally extended and flexed; however, there is only one set of cables attaching to the fingers. The fingers are attached via rubber bands to trolleys which run in grooves through a 190 arc. This unit can accommodate large and small hands, left or right hands, and thick or thin hands. By positioning the hand, either the distal interphalangeal joints can be isolated or the distal and proximal interphalangeal joints can be isolated , or all of the joints can be exercised simultaneously . The hand is exercised while it is being elevated, as seen in this set of photographs . To the left of the thumb is the on-and-off switch, which is easily controlled by the patient. 0
motion over a 1 month period is seen for groups II and III. The mean gain in total active motion for the EDS group (group 1I),was 81.40 ± 24.40 ; by the use of Student's t-test , tliI's was significantly greater (P < 0.01) than the mean gain in group III, which was 49.3° ±
Since repeated statistical analysis may produce spurious findings, the nominal a=level for Student's paired t-test was preserved by the use of Bonferroni method 2.
22S .
Discussion
The mean gain in total passive motion for the EDS group was 72.3° ± 36.9°; by the use of Student's t-test, this was significantly greater (P < 0.01) than the mean gain in group III, which was 50.8° ± 29.0°.
Several interesting findings emerge from the results of this study. First, although the mean gain in total active and passive motion per exercise session for the EDS group was
478
The Journal of HAND SURGERY
Ketchum. Hibbard. Hassanein
Fig. 4. The easiest and most common application of the unit to the fingers is made by placing the open end of a fishing leader through a small drill hole in the fingernail. The leader is attached to a rubber band going to the movable trolleys on the splint. If the patient does not have sufficiently long fingernails, then a small piece of Velcro is glued onto the fingernail, and a small drill hole is made in the Velcro and thus attached. If the patient's fingertips are damaged, as in a burned hand, then a glove is placed on the fingers and an eyelet is placed on the end of the glove, and thus it is attached. Most patients do not mind the small hole in the fingernail, as it enables them to apply the unit to themselves in less than 5 minutes.
Table I. Mean, standard deviation, and standard error of the mean for the change from before to after treatment (L~l) in total active and (a 2) in total passive motion and the difference (d) between a 1 and a 2 for short-term group I Index
Al Mean Standard deviation Standard error of the mean No. Total
P
I
Az
Middle
I
d
Al
I
Az
Ring
I
d
Al
I
A2
Little
I
d
Al
1
A2
Total
1
d
Al
T A2 I
d
16.9 14.2
17.2 12.0
-0.3 10.5
23.2 16.8
23.1 18.5
0.1 24.8
25.0 15.4
19.9 21.6
5.1 14.4
22.2 11.0
15.7 12.0
6.5 16.5
21.8 11.8
19.0 14.9
2.8 14.5
1.6
1.4
1.2
1.9
2.2
2.9
1.8
2.5
1.7
1.3
1.4
1.9
1.4
1.7
1.7
74 10.6
74 12.3
74 12.2
74 10.5
74 8.0
74 11.2
74 11.2
*
*
*
*
*
74 3.4 NS
74 15.6
*
74 3.0 NS
74 17.1
*
74 0.03 NS
74 13.9
*
74 -0.3 NS
74 1.6 NS
*
..
Legend: NS. not significant; No .. number of patients. • Significantly different from zero (P < 0.01).
not significantly different from that of the controls, the long-term gains in both total active motion (TAM) and total passive motion (TPM) were significantly improved in the EDS group. Second, although the mean gain in TAM and TPM per session for the EDS group were 17.8° ± 9.4° and 18S ± 7.3°, respectively, the mean gain from the beginning to the end of the month was only 81.4° ± 24.4° and 72.3° ± 36.9°. This apparent contradiction is explained by looking at the graphs in Fig. 6. It is seen in these two graphs
that the improvement is stair-stepped and that the gain in motion in these fingers is frequently partially lost from the end of one session to the beginning of the next; nevertheless, partial gains accrue over a 1 month period. Third, the mean gain in TAM per session for 1 month in the EDS group was less than the mean shortterm gain, and the mean gain in TPM per session for 1 month (EDS) was greater than the mean short-term gain, though neither of these were significantly different. This indicates that the joints treated continued to
Vol. 4, No.5 September, 1979
Electrically driven hand splint
TROLLEY DRIVE <0"1'_-+_ _ _
479
1
RING _ _ _ _ _-t-_
FLEXION TAB (BLACK) "-'+--+~IIRIf-fe'
DRIVE ARM ----+--l--flIItlIH
ORUH -----+-~f_
EXTENSION TAB (REO) --II--~~
REVERSE ARH
---+--i
REVERSE SWITCH --1.1""'....
Fig. 5. A, The reels going to each finger on the drum can be individually adjusted to accommodate the particular range of motion for that finger. For example, one finger may have a total passive range of motion of 150°, while a neighboring finger would have only 100°, and another finger would have 2(Xf. Each finger would have just a few degrees more excursion than its total passive range of motion. In this way no joint is unduly stressed. The adjustment is made with the patient strapped to the machine and the motor may be stopped in mid-excursion and adjustment made at any time. B, This close-up illustration of the drum shows the mechanism just stopped at the end of the flexion cycle. All flexion tabs are set equally. The extension tabs are shown staggered.
respond well over a 1 month period to this form of stimulation. Fourth, the increase in the mean gain of TAM over TPM for the long-term in the EDS groups was a surprising but welcome finding. An increase in passive motion alone is rewarding but the increase in active motion points to a probable stretching of adhesions of the flexor and extensor tendons, as the case may be, allowing for the increased active motion; however, in the majority of these fingers the passive motion was better than the active motion initially, with greater room for improvement in active motion. Over the last 7 years, the electrically driven splint has been used on over 100 hands; to our knowledge no
finger has been traumatized following this form of exercise. The traction it places on the fingers while going through a range of motion tends to open the joint spaces, which is beneficial.
Summary and conclusions Following the introduction of the electrically driven splint in 1972, the results of improvement in active and passive joint motion were reviewed over the last 12 months and compared with those obtained by passive exercise provided manually by a hand therapist. It was found that, although there was no significant difference in the mean gain in total active and passive motion per exercise session for the two groups, there was a sig-
The Journal of
480
Ketchum, Hibbard, Hassanein
HAND SURGERY
Table II. Mean, standard deviation, and standard error of the mean for the change from before to after treatment (d 1) in total active and (d 2) in total passive motion and the difference (d) between d 1 and d 2 per exercise session for long-term group II and c~ntrol group III /"
Index
Middle
Ring
Little
Total
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
16.3 7.30
18.8 8.1
-2.5 5.1
16.9 8.2
18.5 11.0
-1.6 6.3
18.2 9.8
21.1 8.2
-2.9 6.3
19.7 14.1
15.4 5.0
4.3 13.8
17.8 9.4
18.5 7.3
-0.7 4.5
1.1
1.2
0.8
1.2
1.7
1.0
1.5
1.2
1.0
2.2
0.8
2.1
1.4
1.1
0.7
43 14.8
43 15.7
43 -3.1
43 14.0
43 10.8
43 -1.6
43 12.1
43 17.1
43 -2.9
43 9.0
43 19.3
43 2.0
43 12.7
43 -1.0
NS
•
•
NS
*
•
NS
•
*
NS
*
43 16.8
2
2
2
2
2
Group II: Mean Standard deviation Standard error of the mean No. Total
P Group Ill: Mean Standard deviation Standard error of the mean No. Total
P
*.
*
NS
14.1 4.1
15.6 9.7
-1.5 12.9
15.0 10.2
14.4 7.8
0.6 17.5
11.1 8.6
13.2 3.6
-2.1 10.7
10.7 6.3
12.8 5.3
-2.1 6.2
12.7 6.0
14.0 4.9
-1.3 10.6
0.8
I. 9
2.6
2.0
1.6
3.5
1.7
0.7
2.0
1.3
1.1
1.2
1.2
1.0
2.1
25 17.6
25 8.2
25 -0.6
25 7.5
25 9.0
25 0.2
25 6.4
25 18.8
25 -1.1
25 8.2
25 11.6
25 -1.7
25 10.5
25 14.0
25 -0.6
*
*
NS
t
•
NS
t
NS
*
•
NS
Legend: See Table I. • Significantly different from zero (P t Significantly different from zero (P
*
*
*
NS
< 0.01). < 0.05).
Table III. Standard deviation, and standard error of the mean for the change from before to after treatment (d 1) in total active (d 2) in total passive motion and the difference (d) between d 1 and d 2 for long-term group II and control group III Middle
Index
Ring
Total
Little
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
78.0 30.4
72.3 46.2
5.7 48.8
79.5 37.6
61.4 38.9
18.1 39.6
87.3 33.6
89.4 39.6
-2.1 42.2
81.0 35.6
66.3 29.7
14.7 45.5
81.4 24.4
72.3 36.9
9.1 42.9
4.6
7.0
7.4
5.7
5.9
6.0
4.8
6.0
6.4
5.4
4.5
6.9
3.7
5.6
6.5
43 16.9
43 10.3
43 0.8
43 13.9
43 3.0
43 16.0
43 14.9
43 -0.4
43 15.0
43 14.0
43 2.0
43 21.0
43 12.9
43 1.4
*
*
NS
*
43 10.4
43.3 20.7
48.4 20.8
-5.0 28.8
44.6 27.9
4.1
4.1
5.8
25 10.8
25 11.8
*
*
2
2
2
2
2
Group II: Mean Standard deviation Standard error of the mean No. Total
P Group III: Mean Standard deviation Standard error of the mean No. Total
P
*
*
54.2 26.7
-1.2 35.0
49.3 22.5
50.8 29.0
-1.6 34.5
4.0
5.3
7.0
4.5
5.8
6.9
25 13.3
25 10.2
25 0.2
25 10.9
25 8.6
25 -0.2
NS
*
56.0 22.8
52.0 26.7
4.0 42.3
53.0 20.2
6.1
4.6
5.3
8.5
25 8.1
25 -0.7
25 12.1
25 9.8
25 0.5
*
NS
*
*
NS
*
48.8 29.4
-4.2 30.3
5.5
5.9
25 -0.9
25 8.1
NS
*
• Significantly different from zero (P < 0.01).
NS
*
NS
*
*
*
NS
*
*
*
NS
NS
Vol. 4, No.5 September , 1979
z
§
Electrically driven hand splint
TOTAL ACTIVE AND PASSIVE JOINT MOTION OF THE INDEX AND RING FINGERS OVER A ONE MONTH PERIOD
300
RTPM IT PM
~
w
> (/) (/)
< ~ z < w > ~
~
RTAM ITAM
200 175 150 125
g 75/0 ~-"-----'2-...L3-""4-...L5-..J.6-..J.7--'8'---'-9----'10 ..J
100
f-
EXERCISE SESSIONS TOTAL ACTIVE AND PASSIVE JOINT MOTION OF THE LONG AND RING FINGERS OVER A ONE MONTH PERIOD
z
0
§ :::!E
300 250
Lo..
225
lU
200
0
(!)
z
<[
175
...J
150
a:
<[
I-
0
I-
RTPM LTPM
275
125 100/0
RTAM LTAM
2345678
9
10
EXERCISE SESSIONS
Fig. 6. These grafts depict the stair-step increase in both total active and total passive motion over a 1 month period of time, which explains why, although the mean gain procession in total active motion for the electrically driven splint group was 26.6°, at the end of the month the mean gain was only 75.3°.
481
nificant difference in gain for both total active and passive motion from the beginning to the end of the month for the group treated with the electrically driven splint. Surprisingly the gain in total active motion over a 1 month period of exercise was slightly, though not significantly, greater in active motion over passive exercise. Over the last 7 years this form of continuous gentle exercise has been found to be relatively atraumatic. In addition to providing an improvement in active and passive joint motion, it performs the job in 25% to 50% less time than manual passive exercise, permitting the hand therapist to devote more time to splint fabrication, program planning, progress documentation, and treatment of other patients.
REFERENCES 1. Ketchum LD, Clark LC , Robinson OW, Masters FW: A new electric hand splint. J Bone Joint Surg [Am] 54:902, 1972 2. Wike EL: Data analysis, a statistical primer for psychology students, ed 1. Chicago, New York, 1971, Aldine Atherton Co, pp 71-3
Lynn D. Ketchum, M.D., Ann Hibbard, O.T.R., and Khatab M. Hassanein, Ph.D., Overland Park, Kan.
The electrically driven hand splint (Figs lA, IB, and
IC) was introduced in 1972. Although it was originally designed during the Vietnamese conflict to passively move repaired tendons during the 7 to 8 hours of sleep each day, it has not been used for that purpose to date. Instead, it has been used exclusively to prevent or overcome stiff joints by providing continuous, gentle, reciprocal passive motion. The crude-looking prototype model did accomplish this job. Joint contractures that were resistant to previous efforts of dynamic splinting responded to the electrically driven splint. Use of the machine made it possible to exercise the three joints of each finger (the thumb is not included) in one-fourth of the time it took a therapist and did it as gently, yet more consistently. The extra time allowed the therapist to tend to other aspects of patient care, e.g., splint fabrication, program planning, documentation of progress, etc., or to treatment of another patient. Since 1972 significant improvements have been made in this exercise machine which are diagrammatically depicted in Fig. 2. * The unit is more compact and durable (Fig. 3); it is safer in that it has an easy shut-off control that the patient can use, and Underwriter's Laboratories has approved it as being safe from electrical shock. The unit is easy to set up. The patients quickly learn how to install it for an exercise period
Received for publication March 8, 1979. Reprint requests: Lynn D. Ketchum, M.D., 10550 Quivira Rd., Suite 310, Overland Park, KS 66215.
*Although the concepts of the improvements made were those of the authors, the design and fabrication were made by the engineering department of the Burnett Instrument Co., Lawrence, Kansas.
474
THE JOURNAL OF HAND SURGERY
(Fig. 4). To date eight patients have taken the unit home for a week at a time for daily use. One of the significant improvements is that the range of motion for each finger can be adjusted individually with ease (Fig. 5); this permits each finger to move through a greater or lesser range of motion than any other finger while they are all moving simultaneously. Finally, materials have been used to make the unit light and mobile and to permit the hand to be exercised while in an elevated position. We have evaluated the results of the use of the electrically driven hand splint over the past year and have compared them to those in which stiff joints were passively exercised manually.
Materials and methods Four hundred and twenty-six joints in 142 fingers were studied. They were divided into the following groups: Group I. Short term- 74 fingers: all of the fingers in this group were passively exercised in the electrically driven splint for thirty minutes and the mean gain in total active and passive motion determined. Group II. Forty-three fingers: in this group each finger was passively exercised by the electrically driven splint for 30 minutes twice a week for 4 weeks and the following determinations were made: (1) the mean gain in total active and passive motion per session; and (2) the mean gain in total active and passive motion from the beginning to the end of the month. Group III. Twenty-five fingers: these were the control fingers which were each passively exercised manually by a therapist for 30 minutes twice a week for 4
0363-5023/79/040474+08$00.80/0 © 1979 American Society for Surgery of the Hand
Vol. 4, No.5 September, 1979
Electrically driven hand splint
Fig. lAo The reciprocating mechanism of the motor in which there are two sets of cables going to the fingers: one to the dorsum of the finger and one to the volar side of the finger.
Figs. IB and IC. B, The cables on the dorsal side of the finger have shortened, extending the finger. C, The cables on the volar side of the finger have shortened, flexing the fingers into the palm. Thimbles are used to attach the fingers to the mechanism.
475
476
The Journal of HAND SURGERY
Ketchum, Hibbard. Hassanein
HAND SUPPORT PlATE
FlEXION TAt--~/ DR lYE A M - - - J
LEY DRIVE CORD EXTEHSION TAB
Fig. 2. The device is motor-driven through extension and flexion modes at the rate of 2 cpm. The force of the motor is transmitted through a hidden drive chain to the drum. Mounted on the circumference of the drum are four rings which are driven by drive arms mounted directly on the surface of the drum. The rings have two adjustable tabs that can be moved along the circumference of the ring . The position of these tabs directly relates to the location of the trolleys riding on the curved plastic trolley support. Calibration marks assist in locating the tabs in reference to the desired operating range of the trolleys. Each trolley may be custom set to operate within the tolerance range determined by the therapist.
weeks with the same determinations being made as for Group II. A total of 3,514 measurements were made. Results
The mean short term gains in total active and passive motion for fingers passively exercised by the electrically driven hand splint (group I) are seen in Table I. The mean gain in total active motion was 21.8° ± 11.8°. The mean gain in total passive motion was 19.0° ± 14.9°. Although there was no significant difference statistically between the means for active and passive motion, by the use of Student's paired t-test, there was a significant difference (P < 0.01) between active and passive motion for the amount of motion after therapy as compared with measurements before therapy .
In Table II the mean gain in total active and passive motion per exercise session over a I month period is seen for groups II and III. The mean gain in total active motion for all fingers exercised by the electrically driven splint (EDS) was 17.8° ± 9.4° for group II and 12.7° ± 6.00 for group III, manually exercised. The mean gain in total passive motion for the EDS group was 18.5° ± 7.3° and 14.0° ± 4.9° for the manually exercised group. Again, although there was no significant difference statistically between the two methods per exercise period, by use of Student's paired t-test there was a significant difference (P < 0.01) between both methods regarding both active and passive motion prior to the exercise sessions as compared with the mean measurements after the exercise session. In Table III the mean gain in total active and passive
Vol. 4 , No.5 September, 1979
Electrically driven hand splint
477
Fig. 3. The updated unit, which is more compact. Again, the fingers are reciprocally extended and flexed; however, there is only one set of cables attaching to the fingers. The fingers are attached via rubber bands to trolleys which run in grooves through a 190 arc. This unit can accommodate large and small hands, left or right hands, and thick or thin hands. By positioning the hand, either the distal interphalangeal joints can be isolated or the distal and proximal interphalangeal joints can be isolated , or all of the joints can be exercised simultaneously . The hand is exercised while it is being elevated, as seen in this set of photographs . To the left of the thumb is the on-and-off switch, which is easily controlled by the patient. 0
motion over a 1 month period is seen for groups II and III. The mean gain in total active motion for the EDS group (group 1I),was 81.40 ± 24.40 ; by the use of Student's t-test , tliI's was significantly greater (P < 0.01) than the mean gain in group III, which was 49.3° ±
Since repeated statistical analysis may produce spurious findings, the nominal a=level for Student's paired t-test was preserved by the use of Bonferroni method 2.
22S .
Discussion
The mean gain in total passive motion for the EDS group was 72.3° ± 36.9°; by the use of Student's t-test, this was significantly greater (P < 0.01) than the mean gain in group III, which was 50.8° ± 29.0°.
Several interesting findings emerge from the results of this study. First, although the mean gain in total active and passive motion per exercise session for the EDS group was
478
The Journal of HAND SURGERY
Ketchum. Hibbard. Hassanein
Fig. 4. The easiest and most common application of the unit to the fingers is made by placing the open end of a fishing leader through a small drill hole in the fingernail. The leader is attached to a rubber band going to the movable trolleys on the splint. If the patient does not have sufficiently long fingernails, then a small piece of Velcro is glued onto the fingernail, and a small drill hole is made in the Velcro and thus attached. If the patient's fingertips are damaged, as in a burned hand, then a glove is placed on the fingers and an eyelet is placed on the end of the glove, and thus it is attached. Most patients do not mind the small hole in the fingernail, as it enables them to apply the unit to themselves in less than 5 minutes.
Table I. Mean, standard deviation, and standard error of the mean for the change from before to after treatment (L~l) in total active and (a 2) in total passive motion and the difference (d) between a 1 and a 2 for short-term group I Index
Al Mean Standard deviation Standard error of the mean No. Total
P
I
Az
Middle
I
d
Al
I
Az
Ring
I
d
Al
I
A2
Little
I
d
Al
1
A2
Total
1
d
Al
T A2 I
d
16.9 14.2
17.2 12.0
-0.3 10.5
23.2 16.8
23.1 18.5
0.1 24.8
25.0 15.4
19.9 21.6
5.1 14.4
22.2 11.0
15.7 12.0
6.5 16.5
21.8 11.8
19.0 14.9
2.8 14.5
1.6
1.4
1.2
1.9
2.2
2.9
1.8
2.5
1.7
1.3
1.4
1.9
1.4
1.7
1.7
74 10.6
74 12.3
74 12.2
74 10.5
74 8.0
74 11.2
74 11.2
*
*
*
*
*
74 3.4 NS
74 15.6
*
74 3.0 NS
74 17.1
*
74 0.03 NS
74 13.9
*
74 -0.3 NS
74 1.6 NS
*
..
Legend: NS. not significant; No .. number of patients. • Significantly different from zero (P < 0.01).
not significantly different from that of the controls, the long-term gains in both total active motion (TAM) and total passive motion (TPM) were significantly improved in the EDS group. Second, although the mean gain in TAM and TPM per session for the EDS group were 17.8° ± 9.4° and 18S ± 7.3°, respectively, the mean gain from the beginning to the end of the month was only 81.4° ± 24.4° and 72.3° ± 36.9°. This apparent contradiction is explained by looking at the graphs in Fig. 6. It is seen in these two graphs
that the improvement is stair-stepped and that the gain in motion in these fingers is frequently partially lost from the end of one session to the beginning of the next; nevertheless, partial gains accrue over a 1 month period. Third, the mean gain in TAM per session for 1 month in the EDS group was less than the mean shortterm gain, and the mean gain in TPM per session for 1 month (EDS) was greater than the mean short-term gain, though neither of these were significantly different. This indicates that the joints treated continued to
Vol. 4, No.5 September, 1979
Electrically driven hand splint
TROLLEY DRIVE <0"1'_-+_ _ _
479
1
RING _ _ _ _ _-t-_
FLEXION TAB (BLACK) "-'+--+~IIRIf-fe'
DRIVE ARM ----+--l--flIItlIH
ORUH -----+-~f_
EXTENSION TAB (REO) --II--~~
REVERSE ARH
---+--i
REVERSE SWITCH --1.1""'....
Fig. 5. A, The reels going to each finger on the drum can be individually adjusted to accommodate the particular range of motion for that finger. For example, one finger may have a total passive range of motion of 150°, while a neighboring finger would have only 100°, and another finger would have 2(Xf. Each finger would have just a few degrees more excursion than its total passive range of motion. In this way no joint is unduly stressed. The adjustment is made with the patient strapped to the machine and the motor may be stopped in mid-excursion and adjustment made at any time. B, This close-up illustration of the drum shows the mechanism just stopped at the end of the flexion cycle. All flexion tabs are set equally. The extension tabs are shown staggered.
respond well over a 1 month period to this form of stimulation. Fourth, the increase in the mean gain of TAM over TPM for the long-term in the EDS groups was a surprising but welcome finding. An increase in passive motion alone is rewarding but the increase in active motion points to a probable stretching of adhesions of the flexor and extensor tendons, as the case may be, allowing for the increased active motion; however, in the majority of these fingers the passive motion was better than the active motion initially, with greater room for improvement in active motion. Over the last 7 years, the electrically driven splint has been used on over 100 hands; to our knowledge no
finger has been traumatized following this form of exercise. The traction it places on the fingers while going through a range of motion tends to open the joint spaces, which is beneficial.
Summary and conclusions Following the introduction of the electrically driven splint in 1972, the results of improvement in active and passive joint motion were reviewed over the last 12 months and compared with those obtained by passive exercise provided manually by a hand therapist. It was found that, although there was no significant difference in the mean gain in total active and passive motion per exercise session for the two groups, there was a sig-
The Journal of
480
Ketchum, Hibbard, Hassanein
HAND SURGERY
Table II. Mean, standard deviation, and standard error of the mean for the change from before to after treatment (d 1) in total active and (d 2) in total passive motion and the difference (d) between d 1 and d 2 per exercise session for long-term group II and c~ntrol group III /"
Index
Middle
Ring
Little
Total
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
16.3 7.30
18.8 8.1
-2.5 5.1
16.9 8.2
18.5 11.0
-1.6 6.3
18.2 9.8
21.1 8.2
-2.9 6.3
19.7 14.1
15.4 5.0
4.3 13.8
17.8 9.4
18.5 7.3
-0.7 4.5
1.1
1.2
0.8
1.2
1.7
1.0
1.5
1.2
1.0
2.2
0.8
2.1
1.4
1.1
0.7
43 14.8
43 15.7
43 -3.1
43 14.0
43 10.8
43 -1.6
43 12.1
43 17.1
43 -2.9
43 9.0
43 19.3
43 2.0
43 12.7
43 -1.0
NS
•
•
NS
*
•
NS
•
*
NS
*
43 16.8
2
2
2
2
2
Group II: Mean Standard deviation Standard error of the mean No. Total
P Group Ill: Mean Standard deviation Standard error of the mean No. Total
P
*.
*
NS
14.1 4.1
15.6 9.7
-1.5 12.9
15.0 10.2
14.4 7.8
0.6 17.5
11.1 8.6
13.2 3.6
-2.1 10.7
10.7 6.3
12.8 5.3
-2.1 6.2
12.7 6.0
14.0 4.9
-1.3 10.6
0.8
I. 9
2.6
2.0
1.6
3.5
1.7
0.7
2.0
1.3
1.1
1.2
1.2
1.0
2.1
25 17.6
25 8.2
25 -0.6
25 7.5
25 9.0
25 0.2
25 6.4
25 18.8
25 -1.1
25 8.2
25 11.6
25 -1.7
25 10.5
25 14.0
25 -0.6
*
*
NS
t
•
NS
t
NS
*
•
NS
Legend: See Table I. • Significantly different from zero (P t Significantly different from zero (P
*
*
*
NS
< 0.01). < 0.05).
Table III. Standard deviation, and standard error of the mean for the change from before to after treatment (d 1) in total active (d 2) in total passive motion and the difference (d) between d 1 and d 2 for long-term group II and control group III Middle
Index
Ring
Total
Little
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
.it
I .i I
d
78.0 30.4
72.3 46.2
5.7 48.8
79.5 37.6
61.4 38.9
18.1 39.6
87.3 33.6
89.4 39.6
-2.1 42.2
81.0 35.6
66.3 29.7
14.7 45.5
81.4 24.4
72.3 36.9
9.1 42.9
4.6
7.0
7.4
5.7
5.9
6.0
4.8
6.0
6.4
5.4
4.5
6.9
3.7
5.6
6.5
43 16.9
43 10.3
43 0.8
43 13.9
43 3.0
43 16.0
43 14.9
43 -0.4
43 15.0
43 14.0
43 2.0
43 21.0
43 12.9
43 1.4
*
*
NS
*
43 10.4
43.3 20.7
48.4 20.8
-5.0 28.8
44.6 27.9
4.1
4.1
5.8
25 10.8
25 11.8
*
*
2
2
2
2
2
Group II: Mean Standard deviation Standard error of the mean No. Total
P Group III: Mean Standard deviation Standard error of the mean No. Total
P
*
*
54.2 26.7
-1.2 35.0
49.3 22.5
50.8 29.0
-1.6 34.5
4.0
5.3
7.0
4.5
5.8
6.9
25 13.3
25 10.2
25 0.2
25 10.9
25 8.6
25 -0.2
NS
*
56.0 22.8
52.0 26.7
4.0 42.3
53.0 20.2
6.1
4.6
5.3
8.5
25 8.1
25 -0.7
25 12.1
25 9.8
25 0.5
*
NS
*
*
NS
*
48.8 29.4
-4.2 30.3
5.5
5.9
25 -0.9
25 8.1
NS
*
• Significantly different from zero (P < 0.01).
NS
*
NS
*
*
*
NS
*
*
*
NS
NS
Vol. 4, No.5 September , 1979
z
§
Electrically driven hand splint
TOTAL ACTIVE AND PASSIVE JOINT MOTION OF THE INDEX AND RING FINGERS OVER A ONE MONTH PERIOD
300
RTPM IT PM
~
w
> (/) (/)
< ~ z < w > ~
~
RTAM ITAM
200 175 150 125
g 75/0 ~-"-----'2-...L3-""4-...L5-..J.6-..J.7--'8'---'-9----'10 ..J
100
f-
EXERCISE SESSIONS TOTAL ACTIVE AND PASSIVE JOINT MOTION OF THE LONG AND RING FINGERS OVER A ONE MONTH PERIOD
z
0
§ :::!E
300 250
Lo..
225
lU
200
0
(!)
z
<[
175
...J
150
a:
<[
I-
0
I-
RTPM LTPM
275
125 100/0
RTAM LTAM
2345678
9
10
EXERCISE SESSIONS
Fig. 6. These grafts depict the stair-step increase in both total active and total passive motion over a 1 month period of time, which explains why, although the mean gain procession in total active motion for the electrically driven splint group was 26.6°, at the end of the month the mean gain was only 75.3°.
481
nificant difference in gain for both total active and passive motion from the beginning to the end of the month for the group treated with the electrically driven splint. Surprisingly the gain in total active motion over a 1 month period of exercise was slightly, though not significantly, greater in active motion over passive exercise. Over the last 7 years this form of continuous gentle exercise has been found to be relatively atraumatic. In addition to providing an improvement in active and passive joint motion, it performs the job in 25% to 50% less time than manual passive exercise, permitting the hand therapist to devote more time to splint fabrication, program planning, progress documentation, and treatment of other patients.
REFERENCES 1. Ketchum LD, Clark LC , Robinson OW, Masters FW: A new electric hand splint. J Bone Joint Surg [Am] 54:902, 1972 2. Wike EL: Data analysis, a statistical primer for psychology students, ed 1. Chicago, New York, 1971, Aldine Atherton Co, pp 71-3