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A summary of medical literature on standing exercise effects on bone loss

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    A summary of medical literature on standing exercise effects on bone loss

    Many people of the CareCure Community do passive standing exercises. Over the past year, many people have repeatedly asked for information (see listed topics below) concerning the beneficial effects of standing and recommendations for duration of training. Unfortunately, this information is not available or well-summarized in the medical literature or on Internet. So, I thought that I would try to summarize it here and then polish this later for a full article.

    Spinal cord injury causes demineralization and greater fragility of bone below the injury site. Zehnder, et al. (2004) examined 100 paraplegic men and found that 15 had documented fractures of their lower limbs that increased with time after injury (1% during the first year and 4.6% in those >20 years after injury). Bone loss was greatest in the beginning and leveled off after 1-3 years after injury but there continued to be continuous and progressive loss of cortical bone. Vanwanseele, et al., (2003) at the Swiss Federal Institute of Technology in Zurich found that cartilage deteriorates in the absence of normal joint loading and movement after spinal cord injury. While the atrophy of bone and cartilage is generally attributed to removal of regular weight-bearing activity (Giangregorio & Blimkie, 2002), Edgerton, et al. (2000) has proposed that reduced gravity and prolonged bedrest reduces growth hormone levels.

    Very few studies have documented the beneficial effects of standing in spinal cord injury. Eng, et al. (2001) from the University of Vancouver BC surveyed 152 people with SCI (age 18-55) who stood an average of 40 minutes per session, 3-4 times a week. Perceived benefits of standing included better feelings of well-being, circulation, skin integrity, reflex activity, bowel and bladder function, digestion, sleep, pain, and fatigue. Although the study did not measure any of these benefits, the authors suggested that standing exercise may be beneficial. Ott (2001) suggested that weight-bearing or functional electrical stimulation may prevent some bone loss particularly in acutely injured patients but presented no data to support this suggestion, recommending that estrogen be considered for postmenopausal women, pointing out that bisphophonates "must not be used in recumbant patients", and that thiazides could be useful as adjunct therapy.

    Takata & Yasui (2001) pointed out that reversal of disuse osteoporosis is very slow and require many years, emphasizing that prevention of disuse osteoporosis is the best. de Bruin, et al., (1999) evaluated the efficacy of early mobilization to prevent bone mineral density loss after spinal cord injury. Of 10 subjects who were mobilized early showed no or insignificant loss of trabecular bone and 3 of the 10 showed greater bone strength. Those who were not mobilized showed greater bone loss and also less mechanical bone strength. Early mobilization meant getting the people out of bed.

    Standing may have different effects on tetra- and paraplegics. Faghri, et al. (2001) showed that heart rates increased significantly by 18.2% in paraplegics but only 6% in tetraplegics during passive standing. When the standing was associated with functional electrical stimulation of muscles, the heart rate difference between para- and tetraplegics was not significant. During passive standing, cardiac output, stroke volume and blood pressure decreased whereas as total peripheral resistance increased. In contrast, active (FES) standing maintained all these cardiac parameters.

    Walking with orthothesis is another option. Hawran & Biering-Sorenson (1996) surveyed 45 paraplegic patients who had been prescribed long leg calipers. At the time of the survey, more than 10 years after discharge from hospital, only 3 were still using their calipers. When asked why not, 38% said that it was too time-consuming to put the braces on, 19% said that they were impractical since their hands had to be occupied keeping balance and were not available for carrying things. The 3 patients who still used them only used them at most once a week. However, all the patients who were given access to the standing frame were still using them. They suggested that the standing frame is a good alternative to long leg calipers. Several groups have developed new and lighter orthoses with composite materials (Stallard, et al., 2003).

    Active stepping, such as with the Parastep system, results in increased activity of the heart and lungs, as well as measurable increase in strength, endurance, and bulk of leg muscles (Klose, et al. 1997). Some evidence suggests that functional electrical stimulation and cycling reduced bone loss. Bloomfield, et al., (1996) reported that training with functional electrical stimulation (FES) cycling significantly improved bone mineral density in the leg bones. However, Eser, et al. (2003) studied 38 subjects and showed that FES cycling slowed the rate of bone mineral density loss (i.e. 0.3% per month compared to 0.7% in the control group) but this was not statistically significant. They concluded that FES cycling applied shortly after injury did not significantly attenuate bone loss. Intensive exercise, however, preserves bone mass of upper limbs even though it does not retard demineraliation of the lower body (Jones, et al., 2002).

    Several studies have looked at the effects of physical exercise on bone mass in osteoporotic women. Kronhed & Moller (1998), for example, assessed women who trained for 60 minutes twice a week for a year and fond that they had a significant increase in bone mass density in the greater trochanter (knee). Prior, et al., (1996) and the Osteoporotic Society of Canada concluded that "moderate physical activity in people with osteoporosis can reduce the risk of falls and fractures,...", "may also stimulate bone gain and decrease bone loss", and "its positive effects are an adjunct to other interventions, such as hormonal therapy".

    In summary, standing exercise alone does not seem to prevent lower limb bone loss. However, standing combined with functional electrical stimulation, active walking, and cycling, as well as biphosphonates or other therapies may be effective in reducing bone loss and even restoring bone.

    <UL TYPE=SQUARE>Relevant Topics
    <LI> A number of people on the site recommends standing.
    Who stands?
    <LI> A discussion concerning the need for loading and unloading to promote bone density.
    Which is better -- to stand or to exercize
    <LI> This topic discusses how there is no standard or recommended time for standing, or even documentation of the beneficial effects of standing. How much weightbearing
    Question on Bone loss
    <LI> This topic discusses insurance justification of standing frames.
    rehab center asks why do you want to stand
    Recommendations on standing
    <LI> Here are instructions on how to build your own standing frame. HOW TO BUILD YOU OWN STANDING FRAME
    <LI> Some commercial suppliers of standing frames are given here. In search of a standing frame
    <LI> Stretching before using a standing frame to reduce spasms. Question for standing frame users?[/list]

    <UL TYPE=SQUARE>Cite References
    <LI> Bloomfield SA, Mysiw WJ and Jackson RD (1996). Bone mass and endocrine adaptations to training in spinal cord injured individuals. Bone. 19: 61-8. Department of Health & Kinesiology, Texas A&M University, College Station 77843-4243, USA. To investigate whether exercise training can produce increases in bone mass in spinal cord-injured (SCI) individuals with established disuse osteopenia, nine subjects (age 28.2 years, time since injury 6.0 years, level of injury C5-T7) were recruited for a 9-month training program using functional electrical stimulation cycle ergometry (FES-CE), which produces active muscle contractions in the paralyzed limb. After training, bone mineral density (BMD, by X-ray absorptiometry) increased by 0.047 +/- 0.010 g/cm2 at the lumbar spine; changes in BMD at the femoral neck, distal femur, and proximal tibia were not significant for the group as a whole. In a subset of subjects training at > or = 18 W for at least 3 months (n = 4), BMD increased by 0.095 +/- 0.026 g/cm2 (+18%) at the distal femur. By 6 months of training, a 78% increase in serum osteocalcin was observed, indicating an increase in bone turnover. Urinary calcium and hydroxyproline, indicators of resorptive activity, did not change over the same period. Serum PTH increased 75% over baseline values (from 2.98 +/- 0.15 to 5.22 +/- 0.62 pmol/L) after 6 months' training, with several individual values in hyperparathyroid range; PTH declined toward baseline values by 9 months. These data establish the feasibility of stimulating site-specific increases in bone mass in severely osteopenic bone with muscle contractions independent of weight-bearing for those subjects able to achieve a threshold power output of 18 W with FES-CE. Calcium supplementation from the outset of training in osteopenic individuals may be advisable to prevent training-induced increases in PTH.
    <LI> de Bruin ED, Frey-Rindova P, Herzog RE, Dietz V, Dambacher MA and Stussi E (1999). Changes of tibia bone properties after spinal cord injury: effects of early intervention. Arch Phys Med Rehabil. 80: 214-20. Department of Material Sciences, Laboratory for Biomechanics ETH, Zurich, Switzerland. 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.
    <LI> Edgerton VR, Roy RR, Recktenwald MR, Hodgson JA, Grindeland RE and Kozlovskaya I (2000). Neural and neuroendocrine adaptations to microgravity and ground-based models of microgravity. J Gravit Physiol. 7: 45-52. Brain Research Institute and Department of Physiological Science, University of California, Los Angeles, CA, USA. The functional properties of the motor system of humans and non-human primates are readily responsive to microgravity. There is a growing body of evidence that significant adaptations occur in the spinal cord and muscle in response to prolonged exposure to microgravity. Further, there is evidence that the processing of sensory information from the periphery, particularly that input associated with the function of muscle tendons and joints, is significantly altered as a result of prolonged microgravity. We present evidence that the fundamental neural mechanisms that control the relative activity of the motor pools of a slow and fast extensor muscle is changed such that a slow, postural muscle is less readily activated during locomotion following spaceflight. Another type of change observed in mammals exposed to spaceflight relates to the release of a growth factor, called bioassayable growth hormone, which is thought to be released from the pituitary. When an individual generates a series of isometric plantarflexor contractions, the plasma levels of bioassayable growth hormone increases significantly. This response is suppressed after several days of continuous bedrest or spaceflight. These results suggest a unique neuroendocrine control system and demonstrate its sensitivity to chronic patterns of proprioceptive input associated with load-bearing locomotion.
    <LI> Eng JJ, Levins SM, Townson AF, Mah-Jones D, Bremner J and Huston G (2001). Use of prolonged standing for individuals with spinal cord injuries. Phys Ther. 81 (8): 1392-9. Summary: BACKGROUND AND PURPOSE: Prolonged standing in people with spinal cord injuries (SCIs) has the potential to affect a number of health-related areas such as reflex activity, joint range of motion, or well-being. The purpose of this study was to document the patterns of use of prolonged standing and their perceived effects in subjects with SCIs. SUBJECTS: The subjects were 152 adults with SCIs (103 male, 49 female; mean age=34 years, SD=8, range=18-55) who returned mailed survey questionnaires. METHODS: A 17-item self-report survey questionnaire was sent to the 463 members of a provincial spinal cord support organization. RESULTS: Survey responses for 26 of the 152 respondents were eliminated from the analysis because they had minimal effects from their injuries and did not need prolonged standing as an extra activity. Of the 126 remaining respondents, 38 respondents (30%) reported that they engaged in prolonged standing for an average of 40 minutes per session, 3 to 4 times a week, as a method to improve or maintain their health. The perceived benefits included improvements in several health-related areas such as well-being, circulation, skin integrity, reflex activity, bowel and bladder function, digestion, sleep, pain, and fatigue. The most common reason that prevented the respondents from standing was the cost of equipment to enable standing. DISCUSSION AND CONCLUSION: Considering the many reported benefits of standing, this activity may be useful for people with SCI. This study identified a number of body systems and functions that may need to be investigated if clinical trials of prolonged standing in people with SCI are undertaken. <> School of Rehabilitation Sciences, University of British Columbia, T325- 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T
    <LI> Faghri PD, Yount JP, Pesce WJ, Seetharama S and Votto JJ (2001). Circulatory hypokinesis and functional electric stimulation during standing in persons with spinal cord injury. Arch Phys Med Rehabil. 82: 1587-95. School of Allied Health, University of Connecticut, Storrs, CT 06269-2101, USA. OBJECTIVE: To evaluate the effects of functional electric stimulation (FES) of lower limb muscles during 30 minutes of upright standing on the central and peripheral hemodynamic response in persons with spinal cord injury (SCI). DESIGN: A repeated-measure design. Subjects were used as their own control and underwent 2 testing protocols of FES-augmented standing (active standing) and non-FES standing (passive standing). SETTING: Rehabilitation hospital. PARTICIPANTS: Fourteen individuals with SCI (7 with tetraplegia, 7 with paraplegia). INTERVENTIONS: During active standing, FES was administered to 4 muscle groups of each leg in an overlapping fashion to produce a pumping mechanism during standing. During passive standing, subjects stood for 30 minutes using a standing frame with no FES intervention. MAIN OUTCOME MEASURES: Central hemodynamic responses of stroke volume, cardiac output, heart rate, arterial blood pressure, total peripheral resistance (TPR), and rate pressure product (RPP) were evaluated by impedance cardiography. All measurements were performed during supine and sitting positions before and after standing, and during 30 minutes of upright standing. RESULTS: Comparisons between the groups with paraplegia and tetraplegia showed a significant increase in heart rate in the paraplegics after 30 minutes of active standing. During active standing, paraplegics' heart rate increased by 18.2% (p = .015); during passive standing, it increased by 6% (p = .041). TPR in the tetraplegics significantly (p = .003) increased by 54% when compared with the paraplegics during passive standing. Overall, the tetraplegic group had a significantly lower systolic blood pressure (p = .013) and mean arterial pressure (p = .048) than the paraplegics during passive standing. These differences were not detected during active standing. When data were pooled from both groups and the overall groups response to active and passive standing were compared, the results showed that cardiac output, stroke volume, and blood pressure significantly decreased (p < .05) during 30 minutes of passive standing, whereas TPR significantly increased [p < .05). All of the hemodynamic variables were maintained during 30 minutes of active standing, and there were increases in RPP and heart rate after 30 minutes of active standing. CONCLUSION: FES of the lower extremity could be used by persons with SCI as an adjunct during standing to prevent orthostatic hypotension and circulatory hypokinesis. This effect may be more beneficial to those with tetraplegia who have a compromised autonomic nervous system and may not be able to adjust their hemodynamics to the change in position.
    <LI> Giangregorio L and Blimkie CJ (2002). Skeletal adaptations to alterations in weight-bearing activity: a comparison of models of disuse osteoporosis. Sports Med. 32: 459-76. Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada. 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.
    <LI> Hawran S and Biering-Sorensen F (1996). The use of long leg calipers for paraplegic patients: a follow-up study of patients discharged 1973-82. Spinal Cord. 34: 666-8. Centre for Spinal Cord Injured, Rigshospitalet, The National University Hospital, Denmark. We reviewed the medical records of 45 paraplegic patients discharged with long leg calipers, during the 10 year period 1973-82, from the Rehabilitation Hospital in Hornbaek, Denmark. A follow-up interview was carried out during 1993-94 for all 40 patients who were still alive. Thirty had complete paraplegia (seven women) and 10 had incomplete paraplegia (two women). At the follow-up interview only three were still using their calipers. The main reasons for giving up the use of calipers was, in 38%, that it was too time consuming to put them on and take them off. For 22% the main reason was a fear of falling, while 19% reported that the calipers were impractical, as their hands had to be occupied in keeping balance and therefore could not be used for other purposes, including carrying items. The three paraplegic patients who did not totally give up the use of long leg calipers used them very little, at a maximum once a week. In contrast all 10 paraplegic patients who had been provided with a standing frame made use of this at least once a month. The majority of the remaining subjects were interested in having a standing frame. We therefore believe that a standing frame could be a good alternative to long leg calipers to facilitate standing for spinal cord injured patients.
    <LI> Klose KJ, Jacobs PL, Broton JG, Guest RS, Needham-Shropshire BM, Lebwohl N, Nash MS and Green BA (1997). Evaluation of a training program for persons with SCI paraplegia using the Parastep 1 ambulation system: part 1. Ambulation performance and anthropometric measures. Arch Phys Med Rehabil. 78: 789-93. The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami School of Medicine, FL 33136, USA. OBJECTIVE: To describe performance parameters and effects on anthropometric measures in spinal cord injured subjects training with the Parastep 1 system. DESIGN: Before-after trial. SETTING: Human spinal cord injury applied research laboratory. PARTICIPANTS: Thirteen men and 3 women with thoracic (T4-T11) motor-complete spinal cord injury: mean age, 28.8yrs; mean duration postinjury, 3.8yrs. INTERVENTION: Thirty-two functional neuromuscular stimulation ambulation training sessions using a commercially available system (Parastep-1). The hybrid system consists of a microprocessor-controlled stimulator and a modified walking frame with finger-operated switches that permit the user to control the stimulation parameters and activate the stepping. OUTCOME MEASURES: Distance walked, time spent standing and walking, pace, circumferential (shoulders, chest, abdomen, waist, hips, upper arm, thigh, and calf) and skinfold (chest, triceps, axilla, subscapular, supraillium, abdomen, and thigh) measurements, body weight, thigh cross-sectional area, and calculated lean tissue. RESULTS: Statistically significant changes in distance, time standing and walking, and pace were found. Increases in thigh and calf girth, thigh cross-sectional area, and calculated lean tissue, as well as a decrease in thigh skinfold measure, were all statistically significant. CONCLUSIONS: The Parastep 1 system enables persons with thoracic-level spinal cord injuries to stand and ambulate short distances but with a high degree of performance variability across individuals. The factors that influence this variability have not been completely identified.
    <LI> Jones LM, Legge M and Goulding A (2002). Intensive exercise may preserve bone mass of the upper limbs in spinal cord injured males but does not retard demineralisation of the lower body. Spinal Cord. 40: 230-5. The School of Physical Education, University of Otago, Dunedin, New Zealand. STUDY DESIGN: Cross-sectional study comparing a group of active spinal cord injured (SCI) males carefully matched for age, height, and weight with active able-bodied male controls. OBJECTIVES: To compare bone mass of the total body, upper and lower limbs, hip, and spine regions in active SCI and able-bodied individuals. SETTING: Outpatient study undertaken in two centres in New Zealand. METHODS: Dual energy X-ray absorptiometry (DEXA) scanning was used to determine bone mass. Questionnaires were used to ascertain total time spent in weekly physical activity for each individual. The criterion for entry into the study was regular participation in physical activity of more than 60 min per week, over and above that required for rehabilitation. RESULTS: Seventeen SCI and their able-bodied controls met our required activity criterion. Bone mineral density (BMD) values of the total body and hip regions were significantly lower in the SCI group than in their controls (P=0.0001). Leg BMD and bone mineral content (BMC) were also significantly lower in the SCI group (P=0.0001). By contrast, lumbar spine BMD and arm BMD and BMC did not differ between the SCI and control groups. Arm BMD and BMC were greater (not significant) than the reference norms (LUNAR database) for both groups. CONCLUSION: Intensive exercise regimens may contribute to preservation of arm bone mass in SCI males, but does not prevent demineralisation in the lower body.
    <LI> Kronhed AC and Moller M (1998). Effects of physical exercise on bone mass, balance skill and aerobic capacity in women and men with low bone mineral density, after one year of training--a prospective study. Scand J Med Sci Sports. 8: 290-8. Primary Health Care Centre, Vadstena, Sweden. Vadstena is a small community in the county of Ostergotland, Sweden, where a project began in 1989 to prevent osteoporosis and to lower the expected incidence of osteoporotic fractures. Persons aged 40-70 years who had a low bone mineral density (BMD) value at screening of the distal radius by single-photon absorptiometry (SPA) were invited to participate in a training study during one year. The definition of low BMD was a densitometry value below -1 SD (standard deviation) from a sex- and age-specific reference value (z-score). Fifteen persons wanted to exercise in a group and 15 persons wanted to become a control group. All participants answered a questionnaire about lifestyle, occupation, diseases, medication and heredity. Clinical tests were made regarding mobility of the joints and muscles, balance and physical fitness. BMD for the hip and the lumbar spine were assessed by dual-energy X-ray absorptiometry (DXA) before and after the investigation period. The training programme was carried out for 60 min twice a week during one year and had the intention to improve bone mass, muscle strength and flexibility, balance skill and aerobic capacity. After the training period there was a significant increase in BMD at the greater trochanter (P < 0.01), in balance skill [standing on one leg with closed eyes and "ski step"-test) [P < 0.05) and in oxygen uptake capacity [P < 0.05) in the exercise group. In the control group, there was a significant increase in BMD at the lumbar spine [P < 0.05). However, these results should be judged with caution because several participants were over the age of 60, and at that age degenerative changes in the lumbar spine may increase to a greater or lesser extent. Regular weight-bearing exercises during one year seem to influence BMD at the greater trochanter in a training group comprising both women and men. However, our study was small in number and further training studies are needed to assess the effect of weight-bearing training on bone mass in different sex- and age-specific groups.
    <LI> Ott SM (2001). Osteoporosis in women with spinal cord injuries. Phys Med Rehabil Clin N Am. 12: 111-31. Department of Medicine, University of Washington, Seattle 98195-6426, USA. Decreased bone density and increased fracture risk are seen in patients with SCI. The bone resorption rate is markedly increased. Hypercalciuria, low PTH, and low 1,25 (OH)2 vitamin D are commonly seen. Bed-rest studies show similar findings, but of lesser magnitude. Therapies to treat or prevent osteoporosis include optimal nutrition (with care to avoid exacerbating hypercalciuria). Weight-bearing or functional electrical stimulation cycle ergometry may prevent some of the bone loss, especially in acutely injured patients. Estrogen should be considered in postmenopausal or amenorrheic women, but not if they are at high risk of thromboembolism. More research on effects of estrogen is needed in this population. Bisphosphonates may also help prevent the acute bone loss; oral routes must not be used in recumbent patients. Thiazides could be useful as adjunct therapy.
    <LI> Prior JC, Barr SI, Chow R and Faulkner RA (1996). Prevention and management of osteoporosis: consensus statements from the Scientific Advisory Board of the Osteoporosis Society of Canada. 5. Physical activity as therapy for osteoporosis. Cmaj. 155: 940-4. Department of Medicine, University of British Columbia, Vancouver. OBJECTIVE: To examine exercise as a therapy for people with osteoporosis. OPTIONS: Immobilization, standing low-load and high-load physical activities. OUTCOMES: Risk of injury, quality of life, risk of falls and fractures, strength and posture and pain management. EVIDENCE: Relevant epidemiologic studies, clinical trials and reviews were examined, including the large-scale FICSIT trial in the United States, a prospective 4-year study of women enrolled in an exercise program in Toronto and the large-scale Study of Osteoporotic Fractures. VALUES: Minimizing risk of injury and increasing quality of life were given a high value. BENEFITS, HARMS, AND COSTS: Moderate physical activity in people with osteoporosis can reduce the risk of falls and fractures, decrease pain and improve fitness and overall quality of life. It may also stimulate bone gain and decrease bone loss. Its positive effects are an adjunct to other interventions, such as hormonal therapy. It may give patients the confidence to resume regular activity and can provide social interaction and support. During exercise programs, proper nutrition is necessary to prevent excessive weight loss and impaired immune function resulting from inadequate protein, vitamin and mineral intake. RECOMMENDATIONS: Immobilization should be avoided if possible in anyone with osteoporosis or at increased risk for osteoporosis. Regular, moderate physical activity is recommended for those with osteoporosis. Elderly people should be assessed for risk of falling to identify those in greatest need of an exercise program. Community group exercise programs are beneficial. Younger people with osteoporosis also need exercise that will preserve or improve bone mass, muscular strength, endurance and cardiovascular fitness. Weight loss as a result of physical activity should be avoided and adequate intake of protein, vitamins and minerals assured. Because the benefits of physical activity are independent of the effect of other therapies, physical activity is an essential adjunct to appropriate nutrition and other therapies. Validation: These recommendations were developed by the Scientific Advisory Board of the Osteoporosis Society of Canada at its 1995 Consensus Conference. They are in agreement with the position taken on osteoporosis and exercise by the United States Center for Disease Control and Prevention and the American College of Sports Medicine. SPONSORS: Sponsors of the 1995 conference included the Dairy Farmers of Canada, Eli Lilly Canada, Inc., Hoffmann-La Roche Canada Ltd., Merck Frosst Canada Inc. and Procter & Gamble Pharmaceuticals Canada Inc.
    <LI> Stallard J, McLeod N, Woollam PJ and Miller K (2003). Reciprocal walking orthosis with composite material body brace: initial development. Proc Inst Mech Eng [H]. 217: 385-92. Orthotic Research and Locomotor Assessment Unit, Robert Jones and Agnes Hunt Orthopaedic and District Hospital NHS Trust, Oswestry, Shropshire, UK. Reciprocal walking orthoses are routinely used by thoracic lesion patients for ambulation using crutches. A primary reason for their prescription is to provide therapeutic benefit and improved independence. To achieve this, maximum efficiency of walking and acceptance of the device is necessary to promote long-term compliance. Lateral rigidity in the orthosis influences walking efficiency, but the structural properties of conventional techniques for producing a sufficiently rigid body brace makes them unattractive. Currently patients and clinicians are forced to choose between greater efficiency or cosmesis of the orthosis. Composite materials have the potential to permit the required rigidity in a structure that is less obtrusive. However, their material properties could lead to unsafe forms of failure unless suitable manufacturing methods are devised. It is therefore inappropriate to supply prototypes to patients for field evaluation until laboratory investigation of innovative production methods has ensured that the orthosis is safe. A production technique has been devised that is ostensibly suitable. Prototype body braces have been tested and have been shown to have improved structural properties and safe failure modes. A test programme implemented on a complete concept orthosis has confirmed that improved lateral rigidity can be achieved with a less obtrusive body brace, and that it will behave safely for long enough to permit field evaluation.
    <LI> Takata S and Yasui N (2001). Disuse osteoporosis. J Med Invest. 48: 147-56. Department of Orthopedic Surgery, University of Tokushima School of Medicine, Kuramoto-cho, Tokushima 770-8503, Japan. Reduction of mechanical stress on bone inhibits osteoblast-mediated bone formation and accelerates osteoclast-mediated bone resorption, and leads to what has been called disuse osteoporosis. Prolonged therapeutic bed rest, immobilization due to motor paralysis from injury of the central nervous system or peripheral nerves, application of cast to treat fractures, a common causes of disuse osteoporosis. Imaging diagnosis shows coarse trabecular pattern and thinning of cortical bones. Bone metabolism markers have been used to evaluate bone metabolism. From the viewpoint of bone metabolism, antiresorptive agents should be administered to inhibit bone resorption. Rehabilitation, including bed positioning, therapeutic exercise and electrical stimulation, should be prescribed to subject the atrophied bone to an appropriate level of mechanical stress. In spite of these aggressive and continuous treatments, most cases of disuse osteoporosis require a long time for bone to recover its bone mineral density and strength. Hence, we have to keep in mind that there are no treatments better than prophylaxis of disuse osteoporosis.
    <LI> Vanwanseele B, Eckstein F, Knecht H, Spaepen A and Stussi E (2003). Longitudinal analysis of cartilage atrophy in the knees of patients with spinal cord injury. Arthritis Rheum. 48: 3377-81. Swiss Federal Institute of Technology, Zurich, Switzerland. OBJECTIVE: A previous cross-sectional study indicated that the morphology of patellar and tibial cartilage is subject to change after spinal cord injury (SCI). The aim of this study was to perform a longitudinal analysis of cartilage atrophy in all knee compartments, including the femoral condyles, in SCI patients over 12 months. METHODS: The right knees of 9 patients with complete, traumatic SCI were examined shortly after the injury (mean +/- SD 9 +/- 4 weeks) and at 6 and 12 months postinjury. Three-dimensional morphology of the patellar, tibial, and femoral cartilage (mean and maximum thickness, volume, and surface area) was determined from coronal and transversal magnetic resonance images (fat-suppressed gradient-echo sequences) using validated postprocessing techniques. RESULTS: The mean thickness of knee joint cartilage decreased significantly during the first 6 months after injury (range 5-7%; P < 0.05). The mean change at 12 months was 9% in the patella, 11% in the medial tibia, 11% in the medial femoral condyle, 13% in the lateral tibia, and 10% in the lateral femoral condyle [P < 0.05 for all compartments). CONCLUSION: This is the first report of a longitudinal analysis of cartilage atrophy in patients with SCI. These data show that human cartilage atrophies in the absence of normal joint loading and movement after SCI, with a rate of change that is higher than that observed in osteoarthritis [OA). A potential clinical implication is that cartilage thinning after SCI may affect the stress distribution in the joint and render it vulnerable to OA. Future studies should focus on whether specific exercise protocols and rehabilitation programs can prevent cartilage thinning.
    <LI> Zehnder Y, Luthi M, Michel D, Knecht H, Perrelet R, Neto I, Kraenzlin M, Zach G and Lippuner K (2004). Long-term changes in bone metabolism, bone mineral density, quantitative ultrasound parameters, and fracture incidence after spinal cord injury: a cross-sectional observational study in 100 paraplegic men. Osteoporos Int. Swiss Paraplegic Center, CH-6207, Nottwil, Switzerland. To study the time course of demineralization and fracture incidence after spinal cord injury (SCI), 100 paraplegic men with complete motor loss were investigated in a cross-sectional study 3 months to 30 years after their traumatic SCI. Fracture history was assessed and verified using patients' files and X-rays. BMD of the lumbar spine (LS), femoral neck (FN), distal forearm (ultradistal part = UDR, 1/3 distal part = 1/3R), distal tibial diaphysis (TDIA), and distal tibial epiphysis (TEPI) was measured using DXA. Stiffness of the calcaneus (QUI.CALC), speed of sound of the tibia (SOS.TIB), and amplitude-dependent SOS across the proximal phalanges (adSOS.PHAL) were measured using QUS. Z-Scores of BMD and quantitative ultrasound (QUS) were plotted against time-since-injury and compared among four groups of paraplegics stratified according to time-since-injury (<1 year, stratum I; 1-9 years, stratum II; 10-19 years, stratum III; 20-29 years, stratum IV). Biochemical markers of bone turnover [deoxypyridinoline/creatinine [D-pyr/Cr), osteocalcin, alkaline phosphatase) and the main parameters of calcium phosphate metabolism were measured. Fifteen out of 98 paraplegics had sustained a total of 39 fragility fractures within 1,010 years of observation. All recorded fractures were fractures of the lower limbs, mean time to first fracture being 8.9 +/- 1.4 years. Fracture incidence increased with time-after-SCI, from 1% in the first 12 months to 4.6%/year in paraplegics since >20 years ( p<.01). The overall fracture incidence was 2.2%/year. Compared with nonfractured paraplegics, those with a fracture history had been injured for a longer time [ p<.01). Furthermore, they had lower Z-scores at FN, TEPI, and TDIA [ p<.01 to <.0001), the largest difference being observed at TDIA, compared with the nonfractured. At the lower limbs, BMD decreased with time at all sites [ r=.49 to.78, all p<.0001). At FN and TEPI, bone loss followed a log curve which leveled off between 1 to 3 years after injury. In contrast, Z-scores of TDIA continuously decreased even beyond 10 years after injury. LS BMD Z-score increased with time-since-SCI [ p<.05). Similarly to DXA, QUS allowed differentiation of early and rapid trabecular bone loss [QUI.CALC) vs slow and continuous cortical bone loss [SOS.TIB). Biochemical markers reflected a disproportion between highly elevated bone resorption and almost normal bone formation early after injury. Turnover declined following a log curve with time-after-SCI, however, D-pyr/Cr remained elevated in 30% of paraplegics injured >10 years. In paraplegic men early (trabecular) and persistent (cortical) bone loss occurs at the lower limbs and leads to an increasing fracture incidence with time-after-SCI.[/list]

    Thank you Dr. Young. We look forward to having this available as an article on the homepage!