suggestions from the field
Calculating Weight Bearing On a Tilt Table
W = Patient 's Actual Weight 0 = Angle of Tilt F = Force Down Incline EXAMPLE
ve
F = W X Sine 0 (30 degrees) F = 68 kgs. X .500 F = 34 kgs.
BILLY D. ELAM, MPH
0
w
\
Figure. Analysis of percent of body weight borne on the feet at a tilt of 30 degrees. Sine d = .500.
Referrals for tilt table use often contain in structions for a specific percent of body weight to be borne by the patient. A method of determining percent of body weight borne at specific angles of tilt is presented. A fallacious assumption is that 50 percent of the body weight is borne on the feet when the angle of the table is 45 degrees. In actual ity, 50 percent of the body weight is on the feet when the table is tilted 30 degrees. A judicious application of physics enables the therapist to predetermine the percent of body weight directed down an inclined plane at specific angles of tilt. To determine the percent of body weight (force in kilograms) down the incline, one. must know the weight of the patient and then apply the method used in physics to solve the familiar sliding block problem. Mr. Elam is Assistant Professor, College of Health, De partment of Physical Therapy, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190.
TABLE 1 Percentage of Weight Borne on the Feet at Various Degrees of the Tilt Table Degrees
Sine 0
Percent of Body Weight
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
.000 .087 .174 .259 .342 .423 .500 .574 .643 .707 .766 .819 .866 .906 .940 .966 .985 .996 1.000
0 8.7 17.4 25.9 34.2 42.3 50.0 57.4 64.3 70.7 76.6 81.9 86.6 90.6 94.0 96.6 98.5 99.6 100.0
572
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PHYSICAL THERAPY
When the inclined plane approach is used, the following points should be remembered. Friction between the patient and the tilt table plus the pressure of the safety belts around the patient will affect the accuracy of the reading. Friction and pressure cause the cal culated percent of body weight to be slightly higher than actual value. The contribution of these influences is minimal in the calculation of the problem, however, and for the most part, can be ignored. The Figure illustrates the analysis of this problem. The patient's weight is acting at his center of gravity. The angle of tilt is theta (0). The force that is important is the force di rected down the incline. This force can be
times the sine of the angle of incline (0). Per cent of body weight acting down the plane is then equal to W times sine 0 divided by the weight of the patient and multiplied by 100. Notice the percent of body weight is inde pendent of the actual weight of the patient. The Table lists several angles and their sines as well as the sine in terms of percent of body weight directed down the plane at var ious angles. Tables of sines are readily availa ble for readings from zero to 90 degrees. The information contained in the Table would be useful for therapists to post close to the tilt table for quick and easy reference in deter mining percent of body weight borne at vari ous angles of tilt.
expressed mathematically as body weight (W)
Use of a Sponge to Improve Hand Strength and Coordination RICHARD L. DONTIGNY, BS
A handy, inexpensive exercise device to im prove strength and coordination in the hand is a common household sponge. The sponge, about 5 x 10 x 20 cm, can be natural, latex, or polyurethane foam. With the sponge held in the palm of the hand, each finger can reach out and pull a remaining part of the sponge into the closed hand until all the sponge is in the hand (Fig ure). The fingers extend and adduct or abduct individually as they grasp the sponge. Resist ance increases as more of the sponge is com pressed into the hand. When all of the sponge is compressed, it can be released, and the exercise begun again. The exercise can be varied by changing the position of the sponge in the hand or by using a sponge of different size or shape.
Mr. DonTigny is Chief, Physical Therapy Department, Northern Montana Hospital, PO Box 1231, Havre, MT 59501.
Figure. Fingers exercised by reaching for and pulling sponge into palm.
Volume 56 / Number 5, May 1976
Downloaded from https://academic.oup.com/ptj/article-abstract/56/5/572/4568254 by guest on 12 February 2018
573
Calculating Weight Bearing On a Tilt Table
W = Patient 's Actual Weight 0 = Angle of Tilt F = Force Down Incline EXAMPLE
ve
F = W X Sine 0 (30 degrees) F = 68 kgs. X .500 F = 34 kgs.
BILLY D. ELAM, MPH
0
w
\
Figure. Analysis of percent of body weight borne on the feet at a tilt of 30 degrees. Sine d = .500.
Referrals for tilt table use often contain in structions for a specific percent of body weight to be borne by the patient. A method of determining percent of body weight borne at specific angles of tilt is presented. A fallacious assumption is that 50 percent of the body weight is borne on the feet when the angle of the table is 45 degrees. In actual ity, 50 percent of the body weight is on the feet when the table is tilted 30 degrees. A judicious application of physics enables the therapist to predetermine the percent of body weight directed down an inclined plane at specific angles of tilt. To determine the percent of body weight (force in kilograms) down the incline, one. must know the weight of the patient and then apply the method used in physics to solve the familiar sliding block problem. Mr. Elam is Assistant Professor, College of Health, De partment of Physical Therapy, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190.
TABLE 1 Percentage of Weight Borne on the Feet at Various Degrees of the Tilt Table Degrees
Sine 0
Percent of Body Weight
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
.000 .087 .174 .259 .342 .423 .500 .574 .643 .707 .766 .819 .866 .906 .940 .966 .985 .996 1.000
0 8.7 17.4 25.9 34.2 42.3 50.0 57.4 64.3 70.7 76.6 81.9 86.6 90.6 94.0 96.6 98.5 99.6 100.0
572
Downloaded from https://academic.oup.com/ptj/article-abstract/56/5/572/4568254 by guest on 12 February 2018
PHYSICAL THERAPY
When the inclined plane approach is used, the following points should be remembered. Friction between the patient and the tilt table plus the pressure of the safety belts around the patient will affect the accuracy of the reading. Friction and pressure cause the cal culated percent of body weight to be slightly higher than actual value. The contribution of these influences is minimal in the calculation of the problem, however, and for the most part, can be ignored. The Figure illustrates the analysis of this problem. The patient's weight is acting at his center of gravity. The angle of tilt is theta (0). The force that is important is the force di rected down the incline. This force can be
times the sine of the angle of incline (0). Per cent of body weight acting down the plane is then equal to W times sine 0 divided by the weight of the patient and multiplied by 100. Notice the percent of body weight is inde pendent of the actual weight of the patient. The Table lists several angles and their sines as well as the sine in terms of percent of body weight directed down the plane at var ious angles. Tables of sines are readily availa ble for readings from zero to 90 degrees. The information contained in the Table would be useful for therapists to post close to the tilt table for quick and easy reference in deter mining percent of body weight borne at vari ous angles of tilt.
expressed mathematically as body weight (W)
Use of a Sponge to Improve Hand Strength and Coordination RICHARD L. DONTIGNY, BS
A handy, inexpensive exercise device to im prove strength and coordination in the hand is a common household sponge. The sponge, about 5 x 10 x 20 cm, can be natural, latex, or polyurethane foam. With the sponge held in the palm of the hand, each finger can reach out and pull a remaining part of the sponge into the closed hand until all the sponge is in the hand (Fig ure). The fingers extend and adduct or abduct individually as they grasp the sponge. Resist ance increases as more of the sponge is com pressed into the hand. When all of the sponge is compressed, it can be released, and the exercise begun again. The exercise can be varied by changing the position of the sponge in the hand or by using a sponge of different size or shape.
Mr. DonTigny is Chief, Physical Therapy Department, Northern Montana Hospital, PO Box 1231, Havre, MT 59501.
Figure. Fingers exercised by reaching for and pulling sponge into palm.
Volume 56 / Number 5, May 1976
Downloaded from https://academic.oup.com/ptj/article-abstract/56/5/572/4568254 by guest on 12 February 2018
573
