Wallace
10-07-2004, 11:34 AM
There have been reports of comments made to SEGWAY HT Gliders that the use of such a device is somehow "unhealthy" in the long run. While doing research for a Grant Proposal to the National Institute for Disabilities Rehabilitation Research (NIDRR)I came across this bit of information sent by Stand-N-Go http://members.aol.com/scsweb/private/stdgo.htm
It would indicate that the mere act of standing several times a day offsets the real detriments of a "sitting only" lifestyle. The reduction in circulatory system problems, loss of bone calcium, muscle tone and cardiac function may be counteracted by the simple act of standing up, mounting a SEGWAY and GLIDING.
THERAPEUTIC EFFECTS Of PASSIVE STANDING
-~~~
Passive standing has demonstrated effects on many physiological and psychological functions of the body. This report is a review of the pertinent literature dealing with passive standing and its effects on:
1. Bone demineralization and heterotopic calcification
2. Urinary calculi and bladder function
3. Cardiovascular and pulmonary systems
4. Joint range of motion and muscular tone
5. Morale and ability to perform daily tasks
Perhaps the greatest effect of passive standing is seen in the musculoskeletal system. It has repeatedly been shown that immobilization and disuse of large masses, of muscle and bone produces abnormal losses of bone calcium reduced bone density and hypercalciuria.(2,3,6.7,9,14,16,18)
Claus-Wa1ker et al (5) showed a 46% increase in calciuria following only three days of bed rest in normal men. Donaldson et al (8) found an approximately 83% increase after two weeks. Heany (15), Kaplan et a1 (18). and Abramson (2) demonstrated a link between hypercalciuria and bone loss in immobilized patients. Hypercalciuria and bone density loss have also been associated with soft-tissue ossifications, pathological fractures, and urinary system calcu1i.(2,9)
One of the best studies which showed the effects of passive standing on hypercalcluria was performed by IsseKutz et al.(16) IsseKutz performed several experimental procedures on 14 healthy young men. These experiments involved various periods of bed rest combined with a variety of other activities and exercise. His results showed that 4 hours per- day of supine exercises did not reduce the urinary calcium which was pervious1y elevated by complete bed rest.
Quiet sitting for 8 hours per- day also had no effect on urinary levels of calcium. However, 3 hours per day of quiet standing proved to be sufficient to induce a. slow decline of the elevated calcium excretion in 4 of the 5 subjects. Also included in this s1udy was an investigation of the effects of compressive axial loading on 2 subjects during a, 3 week period of complete bed rest. Axial pressures, equal to the subjects' body weights, were administered daily for 3 hour's.
In one of the subjects the level of urinary calcium declined significantly while in the other- subject, no effect was seen. This evidence has been supported by the results of an axia1 compression and weight bearing exercise program which NASA initiated following discovery of abnormal losses of calcium and reduced bone densities during the Gemini spaceflights (14) Their program of axial loading reduced the rate of bone loss in later spaceflights.(4)
Kaplan et al (1S) studied the effects of at least 20 minutes of daily standing on urinary calcium levels of 10 patients with spinal cord injuries. He found that passive standing significantly decreased hypercalciuria in his 10 subjects.
These results agreed with his earlier work involving hypercalciuria and ambulation in -the patient with paraplegia..(17) Gitman et a,l. (12) showed that 72% of their aged patients who showed osteoporosis were ambulating, however -there was a four fold greater incidence of radiologically severe osteoporosis in bedridden patients.
As mentioned previously, hypercalciuria, which can be a result of decreased weight bearing, is associated with an increased risk of developing urinary calculi and infection which can lead 10 progressive deterioration of renal function if the infection ascends. The incidence of urinary calculi in spinal cord injured patient$ ranges from approximately 30% to over 50%.(7,9) Of these approximately 25% are associated with the kidney and 75% with the bladder. Freeman and others (9,7,2) feel the major disorder in the paraplegic which predisposes him to urinary calculi is the abnormally high withdrawal of calcium from the bones and its excretion in the urine. Freeman's laboratory, analysis of the calculi removed from these patients uniformly
showed calcium and phosphorus as the principle constituents. He feels that early weight bearing reduces the incidence of calculi to such a degree that the presence of a calculus can be taken as an indication of failure to bear weight. This feeling is also shared by Abramson who compared ambulating to nonambulating paraplegics and found significantly lower rates of urinary calculi in, the ambulators.(2)
Aside from the effect on hypercalciuria, passive standing has been shown to increase bladder pressure (13) which can help train the automatic bladder and help decrease the residual volume in the hypotonic bladder.(20)
A significant problem for patients with spinal cord injuries is that of insufficient orthostatic circulatory regulation. Due "to "the loss of sympathetic vascular "tone, the skeletal muscle pump, and a decrease in plasma volume, patients with spinal cord injuries have problems maintaining blood pressure and cardiac output.(10,19) This becomes a. significant problem particularly when cardiac output is insufficient to maintain minimal oxygen requirements for the vita l organs. Although the reason is not fully understood, it is well accepted that repeated and progressive standing can lead to cardiovascular system adaptation producing functional circulation.(19,10.23)
Passive standing has recently been shown to produce significant decreases in muscular tone in patients with spasticity.(21) Following 30 minutes of standing with the feet in a dorsiflexed position, there was a 30% decrease in resistance to passive stretch as compared to only a 17% reduction produced by a similar stretch administered in the supine position. A follow-up study of paraparetic patients who continued passive standing after discharge showed that, without access to regular physical therapy, they were able to maintain adequate range of motion in the hip, knee, and ankle and keep muscular tone at a relatively low level.(22)
Since many tasks of daily living, particularly kitchen tasks, are best performed in the standing position, the use of a portable standing aid can greatly increase the functional status and morale of a person who is otherwise unable to stand.(4) In addition, standing provides pressure relief to skin areas at risk for developing ulceration since most paraplegics spend the majority of their time with pressure on their sacrum and ischial tuberosities.
As one can see, passive standing had been shown to produce several beneficial physiological effects which include:
1. Reduction of bone calcium loss
2. Reduction of hypercalciuria and urinary calculi
3. Muscular tone reduction and maintenance of range of motion
4. Improved orthostatic circulatory regulation
5. Increase bladder pressure
Even without considering these physiological benefits, the cost of passive standing can be justified when one considers the increased independence, productivity, and morale that can be provided by such a device.
~
-~~~
1. Abramson, A.S., Delagi B.F.: Influence of weight bearing and muscle contraction on disuse osteoporosis. Arch Phys Med Rehab 42: 147-151,1961
2. Abramson A.S.: Bone disturbances in injuries to the spinal cord and cauda equina. (paraplegia). J Bone Joint Surg 30A: 982-997, 1948
3. Albright F., Keifenstein E.C.: The parathyroid glands and metabolic bone disease. S e 1 e c t e d S tudies , Williams 8-. WilKins, Baltimore, 1948
4. Birge S.J.. Whedon G.D.: Bone. In hypodynamics and hypogravics: Physiology of inactivity &. weightlessness. Academic Press, New York, 1968
5. Claus-Walker J., Campos R.J., Ca.rter RE., Vallbona C., Uscomb H.S.: Calcium excretion in quadriplegia.. Arch Phys Med Rehab ~3: 14-20, 1972
.6. Cla.us-Walker J., CarieI R.E., Campos R.J., Spencer W.A.: Sitting, muscular
exercises, and collagen metabolism in tetraplegia.. Am J Phys Med 58: 285-293, 1979
7. Com.rr A.&:E: A long-term survey of the incidence of renal calculosis in paraplegia. J Urology 74: 447-452, 1955
8. Donaldson C.L., Hulley S.B., Vogel J.M., Hattner R.S., Buyers J.H., Mc:Millian D.B Effects of prolonged bed rest on bone mineral. Metabolism 19: 1071-1084, 1970
9. Freeman L.W.: The metabolism of calcium in patients with spinal cord injuries. Annals Surgery 129: 177-184, 1949
10. Figoni 8.F.: Cardiovascular and haemodynamic: responses to tilting and 'to standing in teraplegic patients: A review. Paraplegia 22: 99-109, 19:34
11. Geiser M.. Trueta. J.: Muscle action, bone rarefaction and bone formation. J Bone Jt Surg 40: 282-311, 1958
12. Gitman L.. Kamhol12 T., Levin@ J.: Osteoporosis in the aged: Radiographic survey with clinical and biochemical correlations. J Gerontal 13: 43, 1958
13. Gould D. W., Hsieh A.C., Tincller L.F.: The effect of posture on bladder pressure. J Physiol129: 448-453, 1955
14. Hattner R.S., McMillan D.E: Influence of weightlessness upon the skeleton: A review. Aerospace Med 39: 849-855. 1968
15. Heaney R.P.: Radiocalcium metabolism in disuse osteoporosis in man. Am J Med 33t 188-200, 1962
16. IsseKutz B., Blizzard N.C., Rodahl K.: Effects of prolonged bed rest on urinary calcium output. J Applied Physiol 21: 1013-1020, 1966
17. Kaplan P.E.. Gandhavadi E., Richards L., Goldschmidt J.W.: Calcium balance in paraplegic patients: Influence of injury duration and ambulation. Arch Phys Med Rehab 59, 447,1978
18. Kaplan P.E., Roden W., Gilbert g., Richards L., Goldschmidt J.W.: Reduction of hypercalciuria. In tetraplegia. after weight-bearing and strengthening exercises. Paraplegia 19:289-293,1981
19. Krebs M., Ragnarsson K., Tuckman J: Orthostatic vasomotor response in spinal man. Paraplegia 21: 72-80, 1983
20. Machek O. Cohen F.: A new standing table. Am J Occupational Ther 9: 158-160, 1955
21. Odeen I., Knutsson E: Evaluation of the effects of muscle stretch and weight load in patients with spastic palraplegia.. Scand J Rehab Med 13: 117-121, 1981
22. Odeen I.: Efterundersokning av 22 paraplegi-patienter, vardade vid KarolinsKa 5ju~hu5ets neurologiska rehabiliteringsKlinik, 1966-1967. Sjukgymnasten, Iieb i 970
23. Ragnarsson K. T., Krebs M., Naftchi N.g., Demeny M., Sell G.H., Lowman E.W., Tuckman J.: Head-up tilt effect on glomerular filtration rate, renal plasma.flow, and mean arterial pressure in spinal man. Arch Phys Med Rehab 62: 306-310, 19B1
It would indicate that the mere act of standing several times a day offsets the real detriments of a "sitting only" lifestyle. The reduction in circulatory system problems, loss of bone calcium, muscle tone and cardiac function may be counteracted by the simple act of standing up, mounting a SEGWAY and GLIDING.
THERAPEUTIC EFFECTS Of PASSIVE STANDING
-~~~
Passive standing has demonstrated effects on many physiological and psychological functions of the body. This report is a review of the pertinent literature dealing with passive standing and its effects on:
1. Bone demineralization and heterotopic calcification
2. Urinary calculi and bladder function
3. Cardiovascular and pulmonary systems
4. Joint range of motion and muscular tone
5. Morale and ability to perform daily tasks
Perhaps the greatest effect of passive standing is seen in the musculoskeletal system. It has repeatedly been shown that immobilization and disuse of large masses, of muscle and bone produces abnormal losses of bone calcium reduced bone density and hypercalciuria.(2,3,6.7,9,14,16,18)
Claus-Wa1ker et al (5) showed a 46% increase in calciuria following only three days of bed rest in normal men. Donaldson et al (8) found an approximately 83% increase after two weeks. Heany (15), Kaplan et a1 (18). and Abramson (2) demonstrated a link between hypercalciuria and bone loss in immobilized patients. Hypercalciuria and bone density loss have also been associated with soft-tissue ossifications, pathological fractures, and urinary system calcu1i.(2,9)
One of the best studies which showed the effects of passive standing on hypercalcluria was performed by IsseKutz et al.(16) IsseKutz performed several experimental procedures on 14 healthy young men. These experiments involved various periods of bed rest combined with a variety of other activities and exercise. His results showed that 4 hours per- day of supine exercises did not reduce the urinary calcium which was pervious1y elevated by complete bed rest.
Quiet sitting for 8 hours per- day also had no effect on urinary levels of calcium. However, 3 hours per day of quiet standing proved to be sufficient to induce a. slow decline of the elevated calcium excretion in 4 of the 5 subjects. Also included in this s1udy was an investigation of the effects of compressive axial loading on 2 subjects during a, 3 week period of complete bed rest. Axial pressures, equal to the subjects' body weights, were administered daily for 3 hour's.
In one of the subjects the level of urinary calcium declined significantly while in the other- subject, no effect was seen. This evidence has been supported by the results of an axia1 compression and weight bearing exercise program which NASA initiated following discovery of abnormal losses of calcium and reduced bone densities during the Gemini spaceflights (14) Their program of axial loading reduced the rate of bone loss in later spaceflights.(4)
Kaplan et al (1S) studied the effects of at least 20 minutes of daily standing on urinary calcium levels of 10 patients with spinal cord injuries. He found that passive standing significantly decreased hypercalciuria in his 10 subjects.
These results agreed with his earlier work involving hypercalciuria and ambulation in -the patient with paraplegia..(17) Gitman et a,l. (12) showed that 72% of their aged patients who showed osteoporosis were ambulating, however -there was a four fold greater incidence of radiologically severe osteoporosis in bedridden patients.
As mentioned previously, hypercalciuria, which can be a result of decreased weight bearing, is associated with an increased risk of developing urinary calculi and infection which can lead 10 progressive deterioration of renal function if the infection ascends. The incidence of urinary calculi in spinal cord injured patient$ ranges from approximately 30% to over 50%.(7,9) Of these approximately 25% are associated with the kidney and 75% with the bladder. Freeman and others (9,7,2) feel the major disorder in the paraplegic which predisposes him to urinary calculi is the abnormally high withdrawal of calcium from the bones and its excretion in the urine. Freeman's laboratory, analysis of the calculi removed from these patients uniformly
showed calcium and phosphorus as the principle constituents. He feels that early weight bearing reduces the incidence of calculi to such a degree that the presence of a calculus can be taken as an indication of failure to bear weight. This feeling is also shared by Abramson who compared ambulating to nonambulating paraplegics and found significantly lower rates of urinary calculi in, the ambulators.(2)
Aside from the effect on hypercalciuria, passive standing has been shown to increase bladder pressure (13) which can help train the automatic bladder and help decrease the residual volume in the hypotonic bladder.(20)
A significant problem for patients with spinal cord injuries is that of insufficient orthostatic circulatory regulation. Due "to "the loss of sympathetic vascular "tone, the skeletal muscle pump, and a decrease in plasma volume, patients with spinal cord injuries have problems maintaining blood pressure and cardiac output.(10,19) This becomes a. significant problem particularly when cardiac output is insufficient to maintain minimal oxygen requirements for the vita l organs. Although the reason is not fully understood, it is well accepted that repeated and progressive standing can lead to cardiovascular system adaptation producing functional circulation.(19,10.23)
Passive standing has recently been shown to produce significant decreases in muscular tone in patients with spasticity.(21) Following 30 minutes of standing with the feet in a dorsiflexed position, there was a 30% decrease in resistance to passive stretch as compared to only a 17% reduction produced by a similar stretch administered in the supine position. A follow-up study of paraparetic patients who continued passive standing after discharge showed that, without access to regular physical therapy, they were able to maintain adequate range of motion in the hip, knee, and ankle and keep muscular tone at a relatively low level.(22)
Since many tasks of daily living, particularly kitchen tasks, are best performed in the standing position, the use of a portable standing aid can greatly increase the functional status and morale of a person who is otherwise unable to stand.(4) In addition, standing provides pressure relief to skin areas at risk for developing ulceration since most paraplegics spend the majority of their time with pressure on their sacrum and ischial tuberosities.
As one can see, passive standing had been shown to produce several beneficial physiological effects which include:
1. Reduction of bone calcium loss
2. Reduction of hypercalciuria and urinary calculi
3. Muscular tone reduction and maintenance of range of motion
4. Improved orthostatic circulatory regulation
5. Increase bladder pressure
Even without considering these physiological benefits, the cost of passive standing can be justified when one considers the increased independence, productivity, and morale that can be provided by such a device.
~
-~~~
1. Abramson, A.S., Delagi B.F.: Influence of weight bearing and muscle contraction on disuse osteoporosis. Arch Phys Med Rehab 42: 147-151,1961
2. Abramson A.S.: Bone disturbances in injuries to the spinal cord and cauda equina. (paraplegia). J Bone Joint Surg 30A: 982-997, 1948
3. Albright F., Keifenstein E.C.: The parathyroid glands and metabolic bone disease. S e 1 e c t e d S tudies , Williams 8-. WilKins, Baltimore, 1948
4. Birge S.J.. Whedon G.D.: Bone. In hypodynamics and hypogravics: Physiology of inactivity &. weightlessness. Academic Press, New York, 1968
5. Claus-Walker J., Campos R.J., Ca.rter RE., Vallbona C., Uscomb H.S.: Calcium excretion in quadriplegia.. Arch Phys Med Rehab ~3: 14-20, 1972
.6. Cla.us-Walker J., CarieI R.E., Campos R.J., Spencer W.A.: Sitting, muscular
exercises, and collagen metabolism in tetraplegia.. Am J Phys Med 58: 285-293, 1979
7. Com.rr A.&:E: A long-term survey of the incidence of renal calculosis in paraplegia. J Urology 74: 447-452, 1955
8. Donaldson C.L., Hulley S.B., Vogel J.M., Hattner R.S., Buyers J.H., Mc:Millian D.B Effects of prolonged bed rest on bone mineral. Metabolism 19: 1071-1084, 1970
9. Freeman L.W.: The metabolism of calcium in patients with spinal cord injuries. Annals Surgery 129: 177-184, 1949
10. Figoni 8.F.: Cardiovascular and haemodynamic: responses to tilting and 'to standing in teraplegic patients: A review. Paraplegia 22: 99-109, 19:34
11. Geiser M.. Trueta. J.: Muscle action, bone rarefaction and bone formation. J Bone Jt Surg 40: 282-311, 1958
12. Gitman L.. Kamhol12 T., Levin@ J.: Osteoporosis in the aged: Radiographic survey with clinical and biochemical correlations. J Gerontal 13: 43, 1958
13. Gould D. W., Hsieh A.C., Tincller L.F.: The effect of posture on bladder pressure. J Physiol129: 448-453, 1955
14. Hattner R.S., McMillan D.E: Influence of weightlessness upon the skeleton: A review. Aerospace Med 39: 849-855. 1968
15. Heaney R.P.: Radiocalcium metabolism in disuse osteoporosis in man. Am J Med 33t 188-200, 1962
16. IsseKutz B., Blizzard N.C., Rodahl K.: Effects of prolonged bed rest on urinary calcium output. J Applied Physiol 21: 1013-1020, 1966
17. Kaplan P.E.. Gandhavadi E., Richards L., Goldschmidt J.W.: Calcium balance in paraplegic patients: Influence of injury duration and ambulation. Arch Phys Med Rehab 59, 447,1978
18. Kaplan P.E., Roden W., Gilbert g., Richards L., Goldschmidt J.W.: Reduction of hypercalciuria. In tetraplegia. after weight-bearing and strengthening exercises. Paraplegia 19:289-293,1981
19. Krebs M., Ragnarsson K., Tuckman J: Orthostatic vasomotor response in spinal man. Paraplegia 21: 72-80, 1983
20. Machek O. Cohen F.: A new standing table. Am J Occupational Ther 9: 158-160, 1955
21. Odeen I., Knutsson E: Evaluation of the effects of muscle stretch and weight load in patients with spastic palraplegia.. Scand J Rehab Med 13: 117-121, 1981
22. Odeen I.: Efterundersokning av 22 paraplegi-patienter, vardade vid KarolinsKa 5ju~hu5ets neurologiska rehabiliteringsKlinik, 1966-1967. Sjukgymnasten, Iieb i 970
23. Ragnarsson K. T., Krebs M., Naftchi N.g., Demeny M., Sell G.H., Lowman E.W., Tuckman J.: Head-up tilt effect on glomerular filtration rate, renal plasma.flow, and mean arterial pressure in spinal man. Arch Phys Med Rehab 62: 306-310, 19B1