Getting Up Goals

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January/February 2004

By Janice J. Eng, PhD, PT/OT

More than 1,700,000 adults and children in the United States use wheelchairs for daily mobility in their community.¹ People who are dependent on wheelchair mobility and are unable to stand independently may benefit from assistive technology to engage in standing activity. Standing activity can benefit persons with limited mobility resulting from congenital conditions or from musculoskeletal or neurological injuries.

In particular, people with spinal cord injury (SCI) are at great risk for a number of secondary complications due to chronic immobilization, which could be potentially counteracted with regular standing activity. The effects of a SCI are far-reaching and they impact the functioning of multiple body systems including the cardiovascular, respiratory, musculoskeletal, urinary, and digestive systems. Following a SCI, the majority of people experience complications such as pressure sores, urinary tract infections, osteoporosis, contractures, spasticity, and orthostatic hypotension (a drop in blood pressure immediately upon moving to an upright posture, which can result in dizziness and fainting).

Standing devices
The development of devices to enable people with SCI to engage in home-based therapeutic standing activities has been reported as early as the 1960s.² In a survey of a community-based sample of people with SCI, we found that 30% of these individuals engaged in prolonged standing activities as a method to improve or maintain their health.³ Home-based standing activity can be undertaken through different forms of assistive technology, and three general types are described here:

Orthoses
Standing frames and standing wheelchairs
Functional electrical stimulation (FES)

We found that approximately half of the individuals with SCI who participated in regular standing used a standing device while the other half used braces (orthoses) and/or walking aids (forearm crutches, walker).³

Orthoses
Individuals who have some residual motor function of the arms and trunk musculature, but varying motor function of the lower extremities, may be able to engage in standing using conventional orthoses. The conventional knee-ankle-foot orthosis (KAFO) consists of a shoe, ankle joint, knee joint, medial and lateral metal or plastic uprights, calf band, knee pad, and thigh band. The KAFO provides a mechanical support against gravity and locks the knees in extension so they will not collapse. However, it is still possible to tip over or collapse at the hip, and thus, sufficient head, trunk, and hip control is necessary. Forearm crutches or walkers are used in conjunction with the orthoses. Modified versions have a molded ankle-foot orthosis instead of an ankle joint. The reciprocating gait orthosis adds reciprocating hip joints connected by cables, a molded pelvic band, and upright supports for the thorax and can accommodate people with higher thoracic level injuries.

Although the KAFO and reciprocating gait orthosis are intended for ambulation, their high energy cost during walking often results in the use of these orthoses for standing exercise only. For example, one study tracked 147 cases of people with a complete SCI (LI or above) who had been prescribed a Craig-Scott orthosis (modified KAFO), and it was found that more than 50% of these people used the orthosis for therapeutic standing, rather than walking.⁴ Given the cost of customized orthoses, the need for intensive training to use these orthoses safely, and the time and effort to don and doff the braces, other alternative standing devices may be more appropriate if the purpose is only for standing activities.

Standing frames and wheelchairs
Standing frames and standing wheelchairs provide a mechanical support against gravity so the person can maintain an upright posture. The most basic standing frame is a simple padded wooden or metal frame with a wide base, front table attachment for resting the arms, and straps and pads to hold the legs and trunk in the frame. Clients must pull themselves to their standing position or be assisted to standing by a caregiver or mechanical lift.

More expensive devices ($2,000-$6,000) integrate hydraulic or electrical systems to tilt a chair seat and back support forward and upward so that the client rises passively from sitting to rest against a padded frame in the upright standing posture. Space can be an issue in the home setting as these standing frames will require significant floor space and are not easily stored in conventional closets. Standing frames that are fully integrated within a manual or powered wheelchair are also available but are more expensive ($10,000-$20,000). The advantage of the integrated unit is that for some individuals, standing activities can then be incorporated into daily functional activities, such as moving around a workspace and reaching high shelves.

Functional electrical stimulation
A number of FES applications have been used in research to stimulate leg muscles to facilitate a sit-to-stand movement or to maintain a standing posture. There are few standing FES systems that are widely used or commercially available; however, with advances in assistive technology, there will be continuing developments in this area. Many of the FES systems developed for walking incorporate a stimulation pattern for standing. For example, the reciprocating gait orthosis has an integrated electrical stimulation system (Advanced RGO), which can be used to extend the hip and knee to transfer to standing. Another system, a multi-channel electrical stimulation device, enables independent, unbraced standing and ambulation with forearm crutches or a walker in people with SCI. For standing, the quadriceps is stimulated for knee extension while the paraspinals and gluteals are stimulated for trunk stability.

FES standing may have additional benefits compared to passive standing because of the muscle stimulation, in addition to the weight-bearing and upright posture. In fact, FES to the leg muscles may enable people with SCI to stand for longer durations as the FES can facilitate blood circulation via a muscle pump mechanism during standing; this can result in an increase in stroke volume and cardiac output and stabilize blood pressure, thereby reducing the effects of orthostatic hypotension.⁵ On the other hand, the purchase and maintenance cost of a multi-channel FES system can be high, with substantial training required for effective use. In addition, the application of an FES system for standing is more difficult than using a simple standing frame, which is one reason that FES systems are often abandoned after an initial period of use.

Benefits from standing activity
There are a number of potential health benefits to standing for people with SCI, which may prevent, counteract, or lessen the effects of a number of secondary complications including:

Spasticity
Orthostatic hypotension
Osteoporosis
Joint contractures
Constipation
Urinary tract infections
Pressure ulcers
Pain
Sleep dysfunction
Digestive problems
Fatigue

There has been limited research in measuring the physiological effects of standing activity for people with SCI. Many of the conclusions are based on self-reports from people with SCI or are extrapolated from what is known about the physiological benefits of an upright posture in persons without disabilities.

The improvements in spasticity are almost immediate as the resistance to passive ankle joint movement has been found to be reduced following a single 30-minute session on a tilt table positioned near vertical for people with SCI.⁶ However, the benefits may not last that long as there are minimal carryover effects of the reduced spasticity into the next day.⁷ A number of beneficial physiological adaptations to the circulatory system occur with standing. Repeated episodes of standing have been shown to reduce orthostatic hypotension in the acute SCI⁶; however, less is known about cardiovascular or circulatory adaptations that might result from standing activities in the individual with an SCI. The renal system benefits from standing as the glomerular filtration rate, a major indicator of renal system function, has been found to approach normal values in people with tetraplegia when in an upright standing posture, but not in the supine position.⁸ Activities that involve weight-bearing also reduce hypercalciuria (excessive urinary calcium excretion)⁹ which is associated with an increased risk of developing urinary calculi and osteoporosis. In addition to improving bladder function, standing has been reported to improve bowel function by reducing constipation.¹⁰

Although there appears to be a reduction of hypercalciuria with standing, the ability to maintain or improve bone mineral density with this activity is not certain and may depend on the exact nature of the injury, the duration of injury, and the intensity of standing activity. The bone mineral density of the femoral shaft and lumbar spine has been found to be greater in patients who participated in regular passive standing using a standing device, compared to those who did not in individuals at least 1 year postinjury.¹¹ Frey-Rindova and colleagues¹² found no bone density differences between an active group who undertook regular weight-bearing activities in rehabilitation (standing and walking) versus a group who was less active at 1 year post-SCI. In addition, no bone density changes resulted from standing in more chronic SCI populations (average 19 years duration).¹³

Survey studies have found a number of other benefits from standing as reported by individuals with SCI, including improvements in pain, sleep, skin integrity, breathing, digestion, self-care ability, fatigue, and well-being.^3,14 The psychological effects of standing should not be underestimated as demonstrated by comments such as “it feels great to look others in the eye” and “it feels so wonderful to get vertical.”³

Prescription for standing activity
No guidelines exist as to what parameters (eg, frequency, duration) are required to achieve benefits from the practice of standing activities in people with SCI. Thus, current best practice must be inferred from the protocols in the literature that have resulted in health benefits. The majority of studies have selected 30 to 45 minute standing sessions with daily or alternate day use. In a survey response, those who stood at least 1 half hour per day had more positive changes in secondary complications (eg, urinary tract infections, constipation) than those who stood for less than 1 half hour.¹⁵ Thus, it seems that 30-minute sessions would be the minimum required to attain health benefits from standing.

Safety concerns
Standing activity is not without its risks in the SCI population. Clients need to select a standing device that meets their capabilities in terms of the assistance required to transfer into or don the device, the assistance needed to move from sitting to standing, and the necessary body support and stability according to each individual’s function. Dizziness resulting from orthostatic hypotension is common when trying to maintain an upright posture and must be monitored carefully. Given the severe osteoporosis in SCI, it was not surprising that one fracture (out of 99 survey respondents) was reported to result from engaging in standing activity.¹⁵ Thus, it is important that clients be assessed for joint range of motion, bone integrity, cardiovascular responses, and skin breakdown if they have not participated in standing activities recently.

Education and accessibility
Health professionals can play a role in educating clients as to the potential benefits of standing activities and the available equipment on the market. Our survey found that individuals with SCI had a lack of knowledge regarding the potential benefits of standing activities and the necessary equipment to undertake this activity.³ Funding has also been recognized as a major deterrent, and continuing research will help to demonstrate the cost-effectiveness of such devices. It is rare for a simple intervention like this to have the potential for such diverse benefits for so many systems in the body. Improved access and education regarding the use of standing activities could increase the number of people with SCI who might participate in standing.

References

Kaye HS, Kang T, LaPlante MP. Disability Statistics Report—Mobility Device Use in the United States. Washington, DC: US Department of Education, National Institute of Disability and Rehabilitation Research; June 2000.
Kim KH. The Kim Self-Stander for wheelchair patients (a self-help device). Arch Phys Med Rehabil. 1961;42:599-601.
Eng JJ, Levins SM, Townson AF, Mah-Jones D, Bremner J, Huston G. Use of prolonged standing for individuals with spinal cord injuries. Phys Ther. 2001;81:1392-9.
O’Daniel WE Jr, Hahn HR. Follow-up usage of the Scott-Craig Orthosis in paraplegia. Paraplegia. 1981;19:373-8.
Faghri PD, Yount J. Electrically induced and voluntary activation of physiologic muscle pump: a comparison between spinal cord-injured and able-bodied individuals. Clin Rehabil. 2002;16:878-85.
Odeen I, Knutsson E. Evaluation of the effects of muscle stretch and weight load in patients with spastic paraplegia. Scand J Rehabil Med. 1981;13:117-21.
Bohannon RW. Tilt table standing for reducing spasticity after spinal cord injury. Arch Phys Med Rehabil. 1993;74:1121-2.
Ragnarsson KT, Krebs M, Naftchi NE. Head-up tilt effect on glomerular filtration rate, renal plasma flow, and mean arterial pressure in spinal man. Arch Phys Med Rehabil. 1981;62:306-9.
Kaplan PE, Roden W, Gilbert E, Richards L, Goldschmidt JW. Reduction of hypercalciuria in tetraplegia after weight-bearing and strengthening exercises. Paraplegia. 1981;19:289-93.
Hoenig H, Murphy T, Galbraith J, Zolkewitz M. Case study to evaluate a standing table for managing constipation. SCI Nurs. 2001;18:74-77.
Goemaere S, Van Laere M, De Neve P, Kaufman JM. Bone mineral status in paraplegic patients who do or do not perform standing. Osteoporos Int. 1994;4:138-43.
Frey-Rindova P, de Bruin ED, Stussi E, Dambacher MA, Dietz V. Bone mineral density in upper and lower extremities during 12 months after spinal cord injury measured by peripheral quantitative computed tomography. Spinal Cord. 2000;38:26-32.
Kunkel CF, Scremin AME, Eisenberg B, Garcia JF, Roberts S, Martinez S. Effect of “standing” on spasticity, contracture, and osteoporosis in paralyzed males. Arch Phys Med Rehabil. 1993;74:73-8.
Dunn RB, Walter JS, Lucero Y, et al. Follow-up assessment of standing mobility device users. Assist Technol. 1998;10:84-93.
Walter JS, Sola PG, Sacks J, Lucero Y, Langbein E, Weaver F. Indications for a home standing program for individuals with spinal cord injury. J Spinal Cord Med. 1999;22:152-8.

Janice J. Eng, PhD, PT/OT, is an associate professor with the University of British Columbia School of Rehabilitation Sciences, a scientist at the GF Strong Rehab Centre, and associate director (rehabilitation) of the International Collaboration on Repair Discoveries, Vancouver, Canada.