author: Lee JJ, Lyne ED.
publication: J Pediatr Orthop. 1990 Jul-Aug;10(4):497-500.
The incidence (42%) of vitamin D abnormalities is high in severely handicapped children and young adults who sustain fractures, especially those who sustain multiple fractures. Fractures occur primarily in the lower extremity and heal with simple immobilization. In patients with normal vitamin D levels, a history of a significant traumatic event should be identified and child abuse ruled out. Vitamin D-deficient patients respond to nutritional and vitamin D supplementation, with decreased fracture incidence.
author: Miller PR, Glazer DA.
publication: Clin Orthop Relat Res. 1976 Oct;(120):134-7.
This report deals with the treatment of 31 spontaneous fractures which occurred in 50 institutionalized patients who were bedridden primarily because of severe cerebral palsy associated with brain injury. More than one-half of the group sustained a spontaneous fracture. Satisfactory healing of all fractures with a minimum of complications occurred without any immobilization or realignment. In 4 patients with delayed compound wounds, the treatment consisted of resection of the protruding portion of the bone after allowing the bony protrusion to wall itself off.
author: Caulton JM, Ward KA, Alsop CW, Dunn G, Adams JE, Mughal MZ.
publication: Arch Dis Child. 2004 Feb;89(2):131-5.
BACKGROUND: Severely disabled children with cerebral palsy (CP) are prone to low trauma fractures, which are associated with reduced bone mineral density. AIMS: To determine whether participation in 50% longer periods of standing (in either upright or semi-prone standing frames) would lead to an increase in the vertebral and proximal tibial volumetric trabecular bone mineral density (vTBMD) of non-ambulant children with CP. METHODS: A heterogeneous group of 26 pre-pubertal children with CP (14 boys, 12 girls; age 4.3-10.8 years) participated in this randomised controlled trial. Subjects were matched into pairs using baseline vertebral vTBMD standard deviation scores. Children within the pairs were randomly allocated to either intervention (50% increase in the regular standing duration) or control (no increase in the regular standing duration) groups. Pre- and post-trial vertebral and proximal tibial vTBMD was measured by quantitative computed tomography (QCT). RESULTS: The median standing duration was 80.5% (9.5-102%) and 140.6% (108.7-152.2%) of the baseline standing duration in the control group and intervention group respectively. The mean vertebral vTBMD in the intervention group showed an increase of 8.16 mg/cm3 representing a 6% mean increase in vertebral vTBMD. No change was observed in the mean proximal tibial vTBMD. CONCLUSION: A longer period of standing in non-ambulant children with CP improves vertebral but not proximal tibial vTBMD. Such an intervention might reduce the risk of vertebral fractures but is unlikely to reduce the risk of lower limb fractures in children with CP.
author: Gear AJ, Suber F, Neal JG, Nguyen WD, Edlich RF.
publication: J Burn Care Rehabil. 1999 Mar-Apr;20(2):164-9.
The anesthetic skin of patients with spinal cord injuries makes these patients a high-risk population for burn injuries. Innovations in rehabilitation engineering can now provide the disabled with mechanical devices that allow for passive standing. Passive standing has been shown to counteract many of the effects of chronic immobilization and spinal cord injury, including bone demineralization, urinary calculi, cardiovascular instability, and reduced joint range of motion and muscular tone. This article will describe several unique assistive devices that allow for passive standing and an improvement in daily living for people with disabilities.
author: Whedon GD.
publication: J Nutr Sci Vitaminol (Tokyo). 1985 Dec;31 Suppl:S41-4.
Many studies and observations have shown the bone-losing effects of physical inactivity of various forms. Contrariwise, less precise studies and observations have supported the reasonable premise that mechanical loading of the skeleton via physical activity shifts the balance of bone remodeling in favor of bone formation, and appears to do so at all ages. Some interesting starts have been made in research to discover the mechanisms of the action on bone of mechanical loading, but many pathways remain to be explored. Besides the mechanical forces, we need to know more about the interrelations of muscle function, probably mediated through muscle-tendon pull on periosteum, and more about other likely influences, notably changes in circulation to bones. The practical significance relative to calcium metabolism and aging of what has been learned thus far on the effects of activity, is that prolonged inactivity, either in a chair or in bed, is to be avoided, because of its deleterious effects, and that reasonably energetic gravitational exercise, such as walking or possibly jogging, promotes maintenance of bone health.
author: Miller PB, Johnson RL, Lamb Le.
publication: Aerosp Med. 1964 Dec;35:1194-200.
author: Axelson P, Gurski D, Lasko-Harvill A.
publication: RESNA 10th Annual Conference San Jose, California 1987
A broad spectrum of physiological problems are associated with lack of gravitational stress in the individual with spinal cord injury. Prolonged immobilization results in systemic de-adaptations which include cardiovascular changes, the alteration of calcium homeostasis which leads to bone de-mineralization and risk of urinary calculi.
Weight bearing in the standing posture has been shown to ameliorate many of these problems and offers physiological advantages for the individual with spinal card injury.
There are also significant psychological and social benefits to standing, including improved self-image, and eye-to-eye interpersonal contact. Increased vocational, recreational and daily living independence are additional benefits of standing.
author: De Bruin ED, Frey-Rindova P, Herzog RE, Dietz V, Dambacher MA, Stussi E.
publication: Arch Physical Medicine Rehabilitation. 1999 Feb;80(2):214-20.
OBJECTIVE: To evaluate the effectiveness of an early intervention program for attenuating bone mineral density loss after acute spinal cord injury (SCI) and to estimate the usefulness of a multimodality approach in diagnosing osteoporosis in SCI. DESIGN: A single-case, experimental, multiple-baseline design. SETTING: An SCI center in a university hospital. METHODS: Early loading intervention with weight-bearing by standing and treadmill walking. PATIENTS: Nineteen patients with acute SCI. OUTCOME MEASURES: (1) Bone density by peripheral computed tomography and (2) flexural wave propagation velocity with a biomechanical testing method. RESULTS: Analysis of the bone density data revealed a marked decrease of trabecular bone in the nonintervention subjects, whereas early mobilized subjects showed no or insignificant loss of trabecular bone. A significant change was observed in 3 of 10 subjects for maximal and minimal area moment of inertia. Measurements in 19 subjects 5 weeks postinjury revealed a significant correlation between the calculated bending stiffness of the tibia and the maximal and minimal area moment of inertia, respectively. CONCLUSION: A controlled, single-case, experimental design can contribute to an efficient tracing of the natural history of bone mineral density and can provide relevant information concerning the efficacy of early loading intervention in SCI. The combination of bone density and structural analysis could, in the long term, provide improved fracture risk prediction in patients with SCI and a refined understanding of the bone remodeling processes during initial immobilization after injury.
author: Donaldson CL, Hulley SB, Vogel JM, Hattner RS, Bayers JH, McMillan DE.
publication: Metabolism. 1970 Dec; 19(12): 1071-84
Bone mineral is lost during immobilization. This disuse osteopenia occurs locally in patients with fracture or hemiplegia and is generalized in quadriplegia.
author: Giangregorio L, Blimkie CJ.
publication: Sports Med. 2002;32(7):459-76.
The removal of regular weight-bearing activity generates a skeletal adaptive response in both humans and animals, resulting in a loss of bone mineral. Human models of disuse osteoporosis, namely bed rest, spinal cord injury and exposure to micro-gravity demonstrate the negative calcium balance, alterations in biochemical markers of bone turnover and resultant loss of bone mineral in the lower limbs that occurs with reduced weight-bearing loading. The site-specific nature of the bone response is consistent in all models of disuse; however, the magnitude of the skeletal adaptive response may differ across models. It is important to understand the various manifestations of disuse osteoporosis, particularly when extrapolating knowledge gained from research using one model and applying it to another. In rats, hindlimb unloading and exposure to micro-gravity also result in a significant bone response. Bone mineral is lost, and changes in calcium metabolism and biochemical markers of bone turnover similar to humans are noted. Restoration of bone mineral that has been lost because of a period of reduced weight bearing may be restored upon return to normal activity; however, the recovery may not be complete and/or may take longer than the time course of the original bone loss. Fluid shear stress and altered cytokine activity may be mechanistic features of disuse osteoporosis. Current literature for the most common human and animal models of disuse osteoporosis has been reviewed, and the bone responses across models compared.