Effect of electrical stimulation-induced cycling on bone mineral density in spinal cord-injured patients

BACKGROUND: Bone atrophy in spinal cord-injured people (SCI) is, among other factors, caused by immobilization and is initiated shortly after the injury. The present study measured the effect of an functional electrical stimulation (FES)-cycling intervention on bone mineral density (BMD) of the tibia in recently injured SCI people. METHODS: As soon as possible after the injury (mean 4.5 weeks), para- and tetraplegic patients were recruited into an intervention and control group comparable with regard to gender, age, and lesion level. The intervention consisted of 30-min functional electrical stimulation-cycling three times a week for the duration of their primary rehabilitation (mean = 6 months). Computed tomography (CT) scans of the right tibia diaphysis were taken at the beginning and at the end of the intervention. Bone mineral density of cortical bone was calculated from the CT scans. RESULTS: A total of 38 subjects (19 in each group) were included in the study. Both groups showed a reduction in tibial cortical BMD of 0-10% of initial values within 3-10 months. The mean decrease in BMD was 0.3% (+/- 0.6) per month in the intervention group and 0.7% (+/- 0.8) in the control group. This difference did not reach statistical significance. Decrease of BMD was linearly correlated to initial BMD and age in the pooled data of both groups; subjects who had a high initial BMD and/or were older lost more bone. In neither group was bone loss associated with duration of immobilization nor lesion level. CONCLUSIONS: Functional electrical stimulation-cycling applied shortly after SCI did not significantly attenuate bone loss.     

Increases in bone mineral density after functional electrical stimulation cycling exercises in spinal cord injured patients

Purpose. To assess the change in bone mineral density (BMD) after spinal cord injury (SCI) and to evaluate whether BMD loss can be reversed with the intervention of functional electric stimulation cycling exercises (FESCE).

Methods. Fifteen males with SCI were included. Fifteen able-bodied males were also tested to compare BMD. In the SCI group, the FESCE was performed for six months, and then was discontinued in the subsequent six months. BMD was performed before the FESCE, immediately after six months of the FESCE, and at the end of the subsequent six months.

Results. Before the FESCE, the BMD of the SCI subjects in every site, except the lumbar spine, was lower than that of the able-bodied subjects. After six months of FESCE, BMD of the distal femur (DF) and proximal tibia (PT) increased significantly, and BMD of the calcaneus (heel) showed a trend of increase. However, the BMD in the DF, PT, and heel decreased significantly after the subsequent six months without FESCE. The BMD of the femoral neck (FN) decreased progressively throughout the programme.

Conclusions. Our study showed site-specific BMD changes after FESCE. The BMD loss in the DF and PT was partially reversed after six months of FESCE, but the effect faded once the exercise was discontinued.     

Increases in bone mineral density after functional electrical stimulation cycling exercises in spinal cord injured patients

Purpose.?To assess the change in bone mineral density (BMD) after spinal cord injury (SCI) and to evaluate whether BMD loss can be reversed with the intervention of functional electric stimulation cycling exercises (FESCE).

Methods.?Fifteen males with SCI were included. Fifteen able-bodied males were also tested to compare BMD. In the SCI group, the FESCE was performed for six months, and then was discontinued in the subsequent six months. BMD was performed before the FESCE, immediately after six months of the FESCE, and at the end of the subsequent six months.

Results.?Before the FESCE, the BMD of the SCI subjects in every site, except the lumbar spine, was lower than that of the able-bodied subjects. After six months of FESCE, BMD of the distal femur (DF) and proximal tibia (PT) increased significantly, and BMD of the calcaneus (heel) showed a trend of increase. However, the BMD in the DF, PT, and heel decreased significantly after the subsequent six months without FESCE. The BMD of the femoral neck (FN) decreased progressively throughout the programme.

Conclusions.?Our study showed site-specific BMD changes after FESCE. The BMD loss in the DF and PT was partially reversed after six months of FESCE, but the effect faded once the exercise was discontinued.     

Peripheral quantitative computed tomography: measurement sensitivity in persons with and without spinal cord injury

OBJECTIVES: To determine (1) the error attributable to external tibia-length measurements by using peripheral quantitative computed tomography (pQCT) and (2) the effect these errors have on scan location and tibia trabecular bone mineral density (BMD) after spinal cord injury (SCI). DESIGN: Blinded comparison and criterion standard in matched cohorts. SETTING: Primary care university hospital. PARTICIPANTS: Eight able-bodied subjects underwent tibia length measurement. A separate cohort of 7 men with SCI and 7 able-bodied age-matched male controls underwent pQCT analysis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The projected worst-case tibia-length-measurement error translated into a pQCT slice placement error of +/-3 mm. We collected pQCT slices at the distal 4% tibia site, 3 mm proximal and 3 mm distal to that site, and then quantified BMD error attributable to slice placement. RESULTS: Absolute BMD error was greater for able-bodied than for SCI subjects (5.87 mg/cm(3) vs 4.5 mg/cm(3)). However, the percentage error in BMD was larger for SCI than able-bodied subjects (4.56% vs 2.23%). CONCLUSIONS: During cross-sectional studies of various populations, BMD differences up to 5% may be attributable to variation in limb-length-measurement error.     

Electrical stimulation: can it increase muscle strength and reverse osteopenia in spinal cord injured individuals?

OBJECTIVE: To study the extent to which atrophy of muscle and progressive weakening of the long bones after spinal cord injury (SCI) can be reversed by functional electrical stimulation (FES) and resistance training. DESIGN: A within-subject, contralateral limb, and matching design. SETTING: Research laboratories in university settings. PARTICIPANTS: Fourteen patients with SCI (C5 to T5) and 14 control subjects volunteered for this study. INTERVENTIONS: The left quadriceps were stimulated to contract against an isokinetic load (resisted) while the right quadriceps contracted against gravity (unresisted) for 1 hour a day, 5 days a week, for 24 weeks. MAIN OUTCOME MEASURES: Bone mineral density (BMD) of the distal femur, proximal tibia, and mid-tibia obtained by dual energy x-ray absorptiometry, and torque (strength). RESULTS: Initially, the BMD of SCI subjects was lower than that of controls. After training, the distal femur and proximal tibia had recovered nearly 30% of the bone lost, compared with the controls. There was no difference in the mid-tibia or between the sides at any level. There was a large strength gain, with the rate of increase being substantially greater on the resisted side. CONCLUSION: Osteopenia of the distal femur and proximal tibia and the loss of strength of the quadriceps can be partly reversed by regular FES-assisted training.     

The relationship between basal metabolic rate and femur bone mineral density in men with traumatic spinal cord injury

OBJECTIVES: To investigate the relationship between basal metabolic rate (BMR) and hip bone mineral density (BMD) in people with spinal cord injury (SCI) and to determine whether neurologic factors contribute to this relationship. DESIGN: Cross-sectional study. SETTING: Inpatient SCI unit in a rehabilitation hospital. PARTICIPANTS: Thirty men with chronic (time since injury, >1 y) traumatic SCI with an American Spinal Injury Association Impairment Scale grade A or B. Subjects' mean age was 32 years (range, 20-45 y). INTERVENTIONS: All participants were evaluated with neurologic examination to define the level and severity of injury. BMR was determined by indirect calorimetry, and BMD was determined by dual-energy x-ray absorptiometry (DXA). Patients were allocated to osteoporotic, osteopenic, and normal bone density groups according to World Health Organization criteria. DXA was used also to estimate lean- and fat-tissue mass (in kilograms) by standard methods. DXA measurements were performed on the same day as BMR analysis. MAIN OUTCOME MEASURES: DXA and indirect calorimetry. RESULTS: BMR correlated significantly with BMD of the total femur, femur neck, trochanter, and shaft. However, there was no correlation between BMR and femur Ward's triangle. These correlations were stronger in patients with tetraplegia. There was a moderate correlation between BMR and lean tissue mass (r = .66, P < .001), although femur BMD values did not correlate with lean tissue mass in our study group (P > .05). CONCLUSIONS: BMR is closely associated with BMD in men with SCI.     

阿法骨化醇及二膦酸盐类药物对脊髓损伤患者骨密度的影响

目的探讨阿法骨化醇及二膦酸盐类药物对脊髓损伤患者骨密度的影响。方法分别比较 3 1例口服阿法骨化醇与42例未口服该药的脊髓损伤患者 ,以及 2 2例口服二膦酸盐类药物与 2 4例未口服该药的脊髓损伤患者第 4腰椎和股骨近端及其分区骨密度变化的差异。结果是否口服阿法骨化醇对脊髓损伤患者骨密度的保持无显著影响 ;但口服二膦酸盐类药物患者的股骨近端 (total)骨密度较未口服该药物患者下降少 ,两者的差异具有显著性意义 (P <0 .0 5 )。结论口服二膦酸盐类药物对股骨近端的骨密度变化有保护作用。     

Relationship between regional bone density measurements and the time since injury in adults with spinal cord injuries

OBJECTIVES: To determine the bone mineral density (BMD) of the legs, arms, and trunk region of a group of adults with spinal cord injury (SCI) and to determine the relationship between regional BMD values and the time since injury. DESIGN: BMD measurements were determined by total-body, dual-energy x-ray absorptiometry scans and percentage values (percentage-matched BMD), based on manufacturer-supplied normative data for age, sex, body weight, and ethnic group. The relationship between percentage-matched BMD values and time since injury was determined by linear regression analyses. SETTING: Research laboratories in a university setting. PARTICIPANTS: Twenty-nine subjects (21 men, 8 women; mean age, 38.5 y) who had sustained an SCI a mean of 10.6 years earlier (range, 0.6-35.3 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The relationship between percentage-matched BMD values and the time since injury. RESULTS: There was a significant inverse relationship between percentage-matched BMD leg (r2 = -.76), arm (r2 = -.45), and trunk (r2 = -.38) values and the log of time since injury. CONCLUSION: Despite the varying levels of SCI and other relevant BMD contributing factors, the regional percentage-matched BMD values were significantly inversely related to the log of time since injury.     

Bone mineral density after spinal cord injury: a reliable method for knee measurement

OBJECTIVES: To test the interrater reliability of a standardized method to analyze knee bone mineral density (BMD) using dual-energy x-ray absorptiometry (DXA); to compare spine, hip, and knee BMD of people with spinal cord injury (SCI) with able-bodied controls; and to determine the relation between hip BMD and knee BMD in SCI and able-bodied subjects. DESIGN: Criterion standard and masked comparison. SETTING: Primary care university hospital. PARTICIPANTS: A convenience sample of 11 subjects with complete SCI was age and sex matched with 11 able-bodied control subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Four raters analyzed regions of interest according to operational definitions recently developed to standardize the analysis of BMD of the knee. Subjects with chronic SCI and matched controls underwent conventional DXA scans of the spine and hips and "less conventional" scans of the distal femurs and proximal tibias. The relation between hip and knee BMD was analyzed. RESULTS: The knee measurements were highly reliable (femur intraclass correlation coefficient model 2,1 [ICC(2,1)]=.98; tibia ICC(2,1)=.89). Subjects with SCI had lower BMD values than controls at all hip and knee sites (P<.05). Lumbar spine BMD did not differ between groups. Hip BMD was moderately predictive of distal femur BMD (R2=.67), but less correlated with the proximal tibia (R2=.38). CONCLUSIONS: Knee BMD can be reliably analyzed using DXA with this protocol. Subjects with SCI have diminished knee and hip BMD. Low hip BMD is associated with low distal femur BMD.     

Functional electric stimulation-assisted rowing: Increasing cardiovascular fitness through functional electric stimulation rowing training in persons with spinal cord injury

OBJECTIVES: To assess changes in peak functional aerobic power after a 36-session, progressive functional electric stimulation (FES) rowing hybrid training program for persons with spinal cord injury (SCI) and to examine the safety and acceptability of the ROWSTIM II device as well as the integrity of technical modifications to it. DESIGN: Repeated-measures training study, quasi-experimental design, within-person data comparison. SETTING: A university-based recreational physical activity facility for persons with physical disabilities. PARTICIPANTS: Six persons with level C7-T12 SCI (American Spinal Injury Association classes A-C). INTERVENTION: Progressive rowing training program, 30 minutes per session, 3 times a week for 12 weeks at 70% to 75% of pretest peak functional aerobic power during FES rowing on an open loop control, FES-assisted rowing machine. MAIN OUTCOME MEASURES: Total rowing distance, peak functional oxygen consumption, and peak oxygen pulse. RESULTS: Subjects completed between 22 to 36 sessions. After 3 months of training, rowing distance increased by 25% (P<.02), peak oxygen consumption by 11.2% (P<.001), and peak oxygen pulse by 11.4% (P<.01). Heart rate response to hybrid training did not change at the end of training, although peak heart rate with FES lower-extremity exercise increased significantly from pre- to posttraining (P<.01). CONCLUSIONS: Pre- and posttraining peak aerobic power values for ROWSTIM II training were comparable to previously reported values for hybrid cycle and upper-extremity exercise. We conclude that FES-assisted rowing is an effective, safe, and well-tolerated training system for persons with SCI.     

脉冲电磁场及阿仑膦酸钠对脊髓损伤大鼠骨质量的影响

目的探讨早期应用脉冲电磁场（PEMFs）和／或阿仑膦酸钠（ALN）对脊髓损伤（SCI）后大鼠骨质量的影响。方法将62只3月龄雌性sD大鼠随机分为5组，其中假手术组仅行椎板切除术，SCI组、SCI＋ALN组、SCI＋PEMFs组及SCI＋PEMFs＋ALN组行脊髓完全横断术，后3组于术后1周时分别给予ALN和／或PEMFs治疗；于术后8周时取材，检测各组大鼠股骨骨密度值、生物力学指标以及胫骨近端骨组织形态计量学等指标。实验所得数据比较采用单因素方差分析及析因分析。结果早期应用ALN和／或PEMFs均可使股骨骨密度、股骨弹性载荷、最大载荷等生物力学指标增高，胫骨近端骨小梁面积百分比也同时增大，骨小梁宽度增加。结论早期应用ALN和／或PEMFs均可抑制SCI后骨量丢失，增强抗骨折能力，阻止胫骨近端微观结构的退变，提示早期应用ALN及PEMFs有助于防治SCI后骨质疏松，但其具体治疗机制还有待进一步研究。     

Paraplegia-related alterations of bone density in forearm and hip in Greek patients after spinal cord injury

PURPOSE: Paraplegia due to spinal cord injury is related with sublesional bone demineralization with an increased incidence of pathologic fractures in lower extremities. This study was carried out in order to evaluate bone density alterations in forearm and hip in Greek paraplegic patients after spinal cord injury and to correlate the findings with the level of injury, the neurological status, the time interval from injury and the performing of physiotherapy and therapeutic standing. METHOD: Fifty-seven paraplegic patients (33 men and 24 women, with injuries sustained from 6 months to 27 years) and 36 able-bodied age-matched controls (25 men, 16 women) participated in the study. Bone mineral density (BMD) was measured by dual X-ray absorptiometry (DXA) in the proximal and distal forearm, the femoral neck, the greater trochanter and Ward's triangle. Results: The measurements revealed a significant reduction of BMD of femoral neck (p<0.001 in male, p<0.001 in female paraplegics), greater trochanter (p<0.001 and p=0.001, respectively) and Ward's triangle (p=0.001 and p=0.005, respectively). Proximal forearm depicted non-significantly decreased BMD values and distal forearm depicted a slight increase in BMD values. The degree of demineralization was independent of factors such as complete or incomplete spinal cord injury, level of the lesion, physiotherapy and performing of standing. In addition to that, BMD values in both hip and forearm showed no statistically significant correlation with time after injury. CONCLUSIONS: BMD measurements in Greek paraplegic patients reveal bone loss, which most dramatically occurs in the region of hip with a consequent increase of fracture risk. Forearm measurements depict a non-homogeneous response with limited proximal bone loss and slight distal increase of BMD, the latter being possibly attributed to daily activities.     

Asymmetric lower-limb bone loss after spinal cord injury: case report

Osteoporosis is a significant secondary condition that occurs acutely after spinal cord injury (SCI). This article reports on a patient with motor incomplete SCI and asymmetric lower-limb bone loss as it correlates with lower-limb motor function and gait characteristics. A 32-year-old Caucasian male completed a comprehensive inpatient rehabilitation program, including 3 months of robotic body-weight-supported treadmill training three times a week. Bone mineral density (BMD) was monitored up to 1.5 years post-SCI by dual-energy X-ray absorptiometry. Ground reaction forces were measured through an instrumented treadmill for bilateral weight-bearing comparison. At 1.5 years postinjury, neurological examination revealed thoracic 4 American Spinal Injury Association Impairment Scale D SCI with less strength, reduced weight bearing, and lower BMD in the more neurologically impaired leg. These results suggest that osteoporosis may vary according to severity of impairment within individuals and that monitoring lower-limb BMD is especially important for patients who ambulate.     

Effect of pamidronate administration on bone in patients with acute spinal cord injury

Eleven subjects participated in a prospective placebo-controlled trial to address the efficacy of pamidronate in reducing bone loss in persons with acute spinal cord injury (SCI). We administered pamidronate (treatment) or normal saline (placebo) intravenously at baseline (22 to 65 days after injury) and sequentially over 12 months, with follow-up at 18 and 24 months. Regional bone mineral density (BMD) was lost over time, regardless of group. In the treatment group compared with the placebo group, we noted a mild early reduction in loss of total leg BMD. Significant bone loss from baseline occurred earlier in the placebo group at the regional sites than in the treatment group. However, by the end of the treatment and follow-up phases, both groups demonstrated a similar percent bone loss from baseline. Despite an early reduction in bone loss, pamidronate failed to prevent major, long-term bone loss in persons with acute neurologically complete SCI.     

Effect of a vitamin D analog on leg bone mineral density in patients with chronic spinal cord injury

A randomized, placebo-controlled trial was performed to determine the effect of a vitamin D analog (1-alpha-hydroxyvitamin D(2) [1-alpha D(2)]) on the bone mineral density (BMD) in patients with chronic spinal cord injury (SCI). Forty subjects with chronic complete motor SCI were enrolled. The mean plus or minus standard deviation age and duration of injury were 42 plus or minus 12 yr and 11 plus or minus 10 yr, respectively. Either 4 micrograms 1-alpha D(2) (n = 19) or placebo (n = 21) was administered daily for 24 mo. Metabolic markers of bone resorption and formation were obtained. Regional lower-limb dual-energy x-ray absorptiometry was performed at baseline and at 6, 12, 18, and 24 mo. Leg BMD and percent change from baseline significantly increased at 6 (percent change only), 12, 18, and 24 mo in the treatment group, but not in the placebo group. Urinary N-telopeptide, a marker of bone resorption, was significantly reduced during treatment with 1-alpha D(2), but markers of bone formation were not changed.     

Bone mineral and geometric changes through the femur with immobilization due to spinal cord injury

This cross-sectional study describes bone mineral and geometric properties of the midshaft and distal femur in a control population and examines effects of immobilization due to spinal cord injury (SCI) at these skeletal sites. The subject populations were comprised of 118 ambulatory adults (59 men and 59 women) and 246 individuals with SCI (239 men and 7 women); 30 of these were considered to have acute injury (SCI duration <1 year). Bone mineral density (BMD) was assessed at the femoral neck, and midshaft and distal femur by dual energy absorptiometry. Geometric properties, specifically cortical area, polar moment of inertia, and polar section modulus, were estimated at the midshaft from cortical dimensions obtained by concurrent radiography. Reduction in BMD was noted in all femoral regions (27%, 25%, and 43% for femoral neck, midshaft, and distal femur, respectively) compared with controls. In contrast, although endosteal diameter was enlarged, geometric properties were not significantly reduced in the midshaft attributable to the age-related increase in periosteal diameter. These results suggest that simultaneous assessment of bone mineral and geometric properties may improve clinically relevant evaluation of skeletal status.     

Physiologic effects of electrical stimulation leg cycle exercise training in spinal cord injured persons.

The purpose of this study was to assess the physiologic training effects of functional electrical stimulation leg cycle ergometer (FES-LCE) exercise in persons with spinal cord injury (SCI) who were previously untrained in this activity. Ten persons with quadriplegia (C5 to C7) and eight with paraplegia (T4 to T11) performed FES-LCE training on an ERGYS I ergometer 10 to 30 minutes per day, 2 or 3 days per week for 12 to 16 weeks (36 total sessions). Training session power output (PO) ranged from 0.0W (no external resistance) to 30.6W. Each subject completed discontinuous graded FES-LCE and arm crank ergometer (ACE) tests before and after training for determinations of peak lower and upper extremity metabolic, pulmonary, and hemodynamic responses. Compared with pretraining, this SCI group exhibited significantly (p less than or equal to .05) higher posttraining peak PO (+45%), oxygen uptake ([O2], + 23%), pulmonary ventilation (+27%), heart rate (+11%), cardiac output ([Qt], + 13%) and significantly lower total peripheral resistance ([TPR], - 14%) during FES-LCE posttests. There were no significant changes in peak stroke volume (+6%), mean arterial pressure ([MAP], - 5%), or arteriovenous oxygen difference ([a-vO2diff], + 10%) during posttraining FES-LCE tests. In addition, no significant differences were noted for the peak level of any monitored variable during ACE posttests after FES-LCE training. The rise in total vascular conductance, implied by the significant decrease in posttraining TPR during FES-LCE tests, denotes that a peripheral circulatory adaptation developed in the persons with SCI during FES-LCE exercise training.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bone mineral density measured by dual-energy X-ray absorptiometry in normal men

A cross-sectional study of 222 healthy Finnish men aged 20-69 years was performed to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age, and of some physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, Ward's triangle and trochanter) were investigated. The maximal mean BMD was observed at the age of 20-29 years in all the measurement sites. Except for the trochanteric area, BMD diminished along with age, the over-all decrements being 4%, 11%, and 23% in the lumbar, femoral neck and Ward's triangle areas, respectively. BMD was in a positive relationship to weight and height in all the measurement sites. The adjusted (for age, height and weight) BMDs were higher (P less than 0.05) in the group of daily dietary calcium intake greater than 1200 mg as compared with the group of lowest calcium intake (less than 800 mg day-1) in the three femoral areas. Cigarette smoking or alcohol drinking had no obvious effect on BMD.     

Functional electric stimulation: its efficacy and safety in improving pulmonary function and musculoskeletal fitness.

The efficacy and safety of functional electric stimulation (FES) in improving cardiovascular and musculoskeletal fitness in individuals with spinal cord injury was evaluated. Ten males and two females aged 16 to 46 years began an FES program from three months to 22 years after injury. Seven patients had paraplegia and five had quadriplegia. The FES protocol consisted of three phases: (1) leg extension, the stimulation of the quadriceps muscle group only, first without and then with weights; (2) ergometry, the stimulation of quadriceps, hamstrings, and gluteal muscles to produce a bicycling motion; and (3) resistance, the addition of resistance during the bicycling motion described in phase 2. Values for tidal volume, oxygen consumption, and the respiratory quotient were obtained during each phase. Tidal volume and oxygen consumption levels increased significantly (p less than .001) from the start of FES to both the ergometry and the resistance phases. The respiratory quotient improved significantly (p less than .001) from the start of FES to resistance but not from the start of FES to ergometry. Thigh and calf girths were measured at the start of FES and during resistance. Thigh girths increased significantly from the beginning of the program to the resistance phase, p less than .002 for the right leg and p less than .001 for the left. Calf girth, however, showed no significant increase. Based on these improvements and the absence of any serious complications, we believe that FES is an effective and safe method to improve cardiovascular and musculoskeletal fitness in individuals with spinal cord injury.     

Predicting patient-specific rates of bone loss at fracture-prone sites after spinal cord injury

Purpose: People with spinal cord injury (SCI) experience bone loss and have an elevated rate of fracture in the paralysed limbs. The literature suggests an exponential time course of bone loss after SCI, but true rates may vary between patients. We propose systematic evaluation of bone status in the early stages of SCI to identify fast bone losers. Method: A case series of six patients with complete SCI were scanned using peripheral quantitative computed tomography within 5 weeks and at 4, 8 and 12 months post-injury. Bone mineral density (BMD) and bone mineral content (BMC) were measured at fracture-prone sites in the tibia and femur. Patient-specific-predictions (PSP) of expected rates of bone loss were produced by individualising published model equations according to each patient’s measured values at baseline. Wilcoxon Signed-Rank tests were used to identify changes between time-points; chi-squared tests for differences between measured and PSP values. Results: In the lower limbs, mean values decreased significantly between baseline and 8 months post-injury, by 19–31% for trabecular BMD, 21–32% for total BMD, and 9–29% for BMC. Most subjects showed no significant differences between PSP and measured values, but individuals with significantly faster rates of bone loss than predicted should be investigated further. Conclusions: There was considerable intersubject variability in rates of bone loss after SCI. Patients showing the fastest bone loss could benefit from continued follow-up and possibly treatment.

Implications for Rehabilitation

• Spinal cord injury (SCI) leads to extensive muscle paralysis, and is often accompanied by significant bone loss and increased fracture risk.

• Repeat bone scans within months of injury can be used to “red-flag” patients who are losing bone faster than predicted.

• A patient-specific approach to osteoporosis management will facilitate targeted treatment aimed at those who need it most, in SCI and other patient groups.