Gregory D. Summers

High impact exercise increased femoral neck bone mineral density in older men: a randomised unilateral intervention.

INTRODUCTION There is little evidence as to whether exercise can increase BMD in older men with no investigation of high impact exercise. Lifestyle changes and individual variability may confound exercise trials but can be minimised using a within-subject unilateral design (exercise leg [EL] vs. control leg [CL]) that has high statistical power. PURPOSE This study investigated the influence of a 12month high impact unilateral exercise intervention on femoral neck BMD in older men. METHODS Fifty, healthy, community-dwelling older men commenced a 12month high impact unilateral exercise intervention which increased to 50 multidirectional hops, 7days a week on one randomly allocated leg. BMD of both femurs was measured using dual energy X-ray absorptiometry (DXA) before and after 12months of exercise, by an observer blind to the leg allocation. Repeated measures ANOVA with post hoc tests was used to detect significant effects of time, leg and interaction. RESULTS Thirty-five men (mean±SD, age 69.9±4.0years) exercised for 12months and intervention adherence was 90.5±9.1% (304±31 sessions completed out of 336 prescribed sessions). Fourteen men did not complete the 12month exercise intervention due to: health problems or injuries unrelated to the intervention (n=9), time commitments (n=2), or discomfort during exercise (n=3), whilst BMD data were missing for one man. Femoral neck BMD, BMC and cross-sectional area all increased in the EL (+0.7, +0.9 and +1.2 % respectively) compared to the CL (-0.9, -0.4 and -1.2%); interaction effect P<0.05. Although the interaction term was not significant (P>0.05), there were significant main effects of time for section modulus (P=0.044) and minimum neck width (P=0.006). Section modulus increased significantly in the EL (P=0.016) but not in the CL (P=0.465); mean change +2.3% and +0.7% respectively, whereas minimum neck width increased significantly in the CL (P=0.004) but not in the EL (P=0.166); mean changes being +0.7% and +0.3% respectively. CONCLUSION A 12month high impact unilateral exercise intervention was feasible and effective for improving femoral neck BMD, BMC and geometry in older men. Carefully targeted high impact exercises may be suitable for incorporation into exercise interventions aimed at preventing fractures in healthy community-dwelling older men.

Risk factors for stress fracture in female endurance athletes : a cross-sectional study

Objective To identify psychological and physiological correlates of stress fracture in female endurance athletes. Design A cross-sectional design was used with a history of stress fractures and potential risk factors assessed at one visit. Methods Female-endurance athletes (58 runners and 12 triathletes) aged 26.0±7.4 years completed questionnaires on stress fracture history, menstrual history, athletic training, eating psychopathology and exercise cognitions. Bone mineral density, body fat content and lower leg lean tissue mass (LLLTM) were assessed using dual-x-ray absorptiometry. Variables were compared between athletes with a history of stress fracture (SF) and those without (controls; C) using χ², analysis of variance and Mann-Whitney U tests. Results Nineteen (27%) athletes had previously been clinically diagnosed with SFs. The prevalence of current a/oligomenorrhoea and past amenorrhoea was higher in SF than C (p=0.008 and p=0.035, respectively). SF recorded higher global scores on the eating disorder examination questionnaire (p=0.049) and compulsive exercise test (p=0.006) and had higher LLLTM (p=0.029) compared to C. These findings persisted with weight and height as covariates. In multivariate logistic regression, compulsive exercise, amenorrhoea and LLLTM were significant independent predictors of SF history (p=0.006, 0.009 and 0.035, respectively). Conclusions Eating psychopathology was associated with increased risk of SF in endurance athletes, but this may be mediated by menstrual dysfunction and compulsive exercise. Compulsive exercise, as well as amenorrhoea, is independently related to SF risk.

The Influence of High-Impact Exercise on Cortical and Trabecular Bone Mineral Content and 3D Distribution Across the Proximal Femur in Older Men: A Randomized Controlled Unilateral Intervention

Regular exercisers have lower fracture risk, despite modest effects of exercise on bone mineral content (BMC). Exercise may produce localized cortical and trabecular bone changes that affect bone strength independently of BMC. We previously demonstrated that brief, daily unilateral hopping exercises increased femoral neck BMC in the exercise leg versus the control leg of older men. This study evaluated the effects of these exercises on cortical and trabecular bone and its 3D distribution across the proximal femur, using clinical CT. Fifty healthy men had pelvic CT scans before and after the exercise intervention. We used hip QCT analysis to quantify BMC in traditional regions of interest and estimate biomechanical variables. Cortical bone mapping localized cortical mass surface density and endocortical trabecular density changes across each proximal femur, which involved registration to a canonical proximal femur model. Following statistical parametric mapping, we visualized and quantified statistically significant changes of variables over time in both legs, and significant differences between legs. Thirty‐four men aged mean (SD) 70 (4) years exercised for 12‐months, attending 92% of prescribed sessions. In traditional regions of interest, cortical and trabecular BMC increased over time in both legs. Cortical BMC at the trochanter increased more in the exercise than control leg, whereas femoral neck buckling ratio declined more in the exercise than control leg. Across the entire proximal femur, cortical mass surface density increased significantly with exercise (2.7%; p < 0.001), with larger changes (> 6%) at anterior and posterior aspects of the femoral neck and anterior shaft. Endocortical trabecular density also increased (6.4%; p < 0.001), with localized changes of > 12% at the anterior femoral neck, trochanter, and inferior femoral head. Odd impact exercise increased cortical mass surface density and endocortical trabecular density, at regions that may be important to structural integrity. These exercise‐induced changes were localized rather than being evenly distributed across the proximal femur.

ATYPICAL FEMORAL FRACTURE IN OSTEOPOROSIS PSEUDOGLIOMA SYNDROME ASSOCIATED WITH TWO NOVEL COMPOUND HETEROZYGOUS MUTATIONS IN LRP5

Osteoporosis pseudoglioma syndrome (OPPG) is a rare autosomal recessive condition of congenital blindness and severe childhood osteoporosis with skeletal fragility, caused by loss‐of‐function mutations in the low‐density lipoprotein receptor‐related protein 5 (LRP5) gene. We report the first case of atypical (subtrochanteric) femoral fracture (AFF) in OPPG, occurring in a 38‐year‐old man within the context of relatively low bone turnover and trabecular osteoporosis on bone histology. We identify two novel LRP5 mutations: R752W is associated with low bone mineral density (BMD), as demonstrated by the heterozygous carriage identified in his 57‐year‐old mother; however, the combination of this R752W mutation with another novel W79R mutation, causes a severe case of compound heterozygous OPPG. We undertake 3D homology modeling of the four extracellular YWTD β‐propeller/EGF‐like domains (E1–E4) of LRP5, and show that both novel mutations destabilize the β‐propeller domains that are critical for protein and ligand binding to regulate Wnt signaling and osteoblast function. Although AFFs have been reported in other rare bone diseases, this is the first in a genetic condition of primary osteoblast dysfunction. The relatively low bone turnover observed, and knowledge of LRP5 function, implicates impaired bone remodeling in the pathogenesis of AFF.

Stress fracture injury in female endurance athletes in the United Kingdom: A 12‐month prospective study

Studies of stress fracture (SF) incidence are limited in number and geographical location; this study determined the incidence of SF injury in female endurance athletes based in the United Kingdom. A total of 70 athletes aged between 18 and 45 years were recruited and prospectively monitored for 12 months. Questionnaires at baseline and 12 months assessed SF, menstrual and training history, eating psychopathology, and compulsive exercise. Peak lower leg muscle strength was assessed in both legs using an isometric muscle rig. Bone mineral density (BMD) of total body, spine, hip, and radius was assessed using dual X‐ray absorptiometry. Among the 61 athletes who completed the 12‐month monitoring, two sustained a SF diagnosed by magnetic resonance imaging, giving an incidence rate (95% confidence intervals) of 3.3 (0.8, 13.1) % of the study population sustaining a SF over 12 months. The SF cases were 800 m runners aged 19 and 22 years, training on average 14.2 h a week, eumenorrheic with no history of menstrual dysfunction. Case 1 had a higher than average energy intake and low eating psychopathology and compulsive exercise scores, while the reverse was true in case 2. BMD in both cases was similar to mean values in the non‐SF group. The incidence of SF in our female endurance athlete population based in the United Kingdom was 3.3%, which is lower than previously reported. Further work is needed to confirm the current incidence of SF and evaluate the associated risk factors.

201. PHYSICAL ACTIVITY LEVELS IN FEMALE RHEUMATOID ARTHRITIS PATIENTS ON LONG TERM ANTI-TUMOUR NECROSIS FACTOR THERAPY COMPARED TO PATIENTS WITH ACTIVE RHEUMATOID DISEASE AND HEALTHY CONTROLS

Background: Anti-TNF therapy has revolutionised the management of rheumatoid arthritis (RA) with rapid and sustained improvements in pain, function and quality of life. However, we do not know how this impacts upon habitual daily physical activity and whether treated patients attain activity levels seen in healthy controls. This study aimed to compare the physical activity levels of patients whose RA was well controlled on long-term anti-TNF therapy to RA patients with active arthritis and non-RA controls. Methods: Participants were patients on anti-TNF for more than two years (tRA) with DAS 3.2 (aRA) and healthy controls (C), matched for age and BMI. Physical activity was assessed using the Actigraph GT3x+ accelerometer, worn throughout waking hours for seven days to determine time spent in light activity, moderate to vigorous physical activity (MVPA) and sedentary time. The International Physical Activity Questionnaire (IPAQ) was also completed. Groups were compared using analysis of variance with Bonferroni post hoc tests; Kruskal-Wallis or Mann-Whitney U- test as appropriate. Results: RA disease duration was significantly greater in tRA than aRA. Groups did not differ significantly in age, height, weight or body mass index (Table). Daily step count was significantly lower in aRA than tRA and C. Sedentary time (as a proportion of wear time) was significantly greater in aRA than tRA, whilst the reverse was true for light activity time. MVPA time was significantly lower in both RA groups than in controls. IPAQ questionnaires demonstrated significant differences between groups, with substantially higher values in C than RA groups in total METs and MET-minutes per week in domestic and garden, leisure, walking activities as well as total moderate and vigorous activities. RA patients had lower moderate to vigorous activity time than controls, regardless of treatment. aRA had lower light activity time, and more sedentary time, than tRA Conclusion: Moderate to vigorous physical activity should be promoted in all RA patients as even those with well controlled disease exhibit a deficit in comparison to controls

Bone density changes following stress fracture in female athletes

BACKGROUND: Poor lower limb stability during dynamic movement is thought to increase the risk of musculoskeletal injury. Biomechanically, stability is determined by a number of factors including the external load and contributions from passive and active tissues. One approach for studying lower limb stability is the single leg squat (SLS) test, which requires coordinated lower limb movement across a range of joint motions under external load. Although clinicians typically assess SLS quality from a single point of view (i.e. frontal plane), a 3D investigation of SLS kinematics would help to determine factors that differentiate clinician-defined “good” from “poor” quality performance. PURPOSE: To determine the kinematic parameters that characterise a good or a poor SLS performance in young adults. METHODS: 22 healthy young adults (13 male, 9 female; age: 23.8 ±3.1 years; height: 1.73 ±0.07 m; mass: 69.4 ±12.7 kg) free from musculoskeletal impairment were recruited. Video footage was collected in the frontal plane as participants performed three SLSs on each leg. SLS quality was assessed by a panel of physiotherapists using a ten-point ordinal scale. Performances were subsequently divided into tertiles corresponding to poor, intermediate and good SLS technique. 3D trajectories of 28 reflective markers attached to the pelvis, and lower limbs were simultaneously recorded at 200 Hz using a 10-camera, motion capture system (Vicon Motion Systems, Oxford, UK). Pelvis, hip and knee angles were calculated using a validated lower limb biomechanical model that incorporated functional identification of hip and knee joint centres. RESULTS: Mean rating of SLS quality as assessed by the panel of physiotherapists was 6.3±1.9 (range: 2.4 - 9.1). 3D analysis of SLS performance revealed that poor squatters had increased hip adduction (22.4 ±6.1 vs 14.7 ±4.7 deg, p<0.01), reduced knee flexion (73.1 ±8.7 vs 90.1 ±12.1 deg, p<0.01) and increased medal-lateral displacement of the knee joint centre (53.7 ±16.8 vs 38.4 ±14.3 mm, p=0.02) compared to good squatters. CONCLUSION: In healthy young adults a poor SLS is characterised by inadequate knee flexion and excessive frontal plane motion at the knee and hip. It is recommended that clinicians standardise knee flexion angle when using the SLS test as it might confound the perception of SLS quality.Purpose: To evaluate changes in performance and cardiac autonomic control (i.e. heart rate [HR] variability [HRV]) in elite soccer players during their pre-season training regime. Methods: Eight Spanish Premier League soccer players were examined at the first (week 1) and the last week (week 8) of the pre-season period (July-September). Nocturnal HR recordings on 4 days per week were averaged to evaluate the weekly HRV. Players also completed the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) for the assessment of specific fitness. Results: During the pre-season period, there was no significant change (4.5 ± 23.9%) in Yo-Yo IR1 performance (2,475 ± 421 vs. 2,600 ± 786 m, p=0.55), while there was a significant decrement (6.3 ± 4.3%) in maximal HR (HRmax) recorded during the test (191 ± 7 vs. 179 ± 8 bpm, p = 0.004). Over the 8-week pre-season, significant increases in the standard deviation of the long-term continuous HRV (SD2) (174 ± 56 vs. 212 ± 53 ms, p = 0.017), and in the standard deviation of all HR intervals (SDNN) (135 ± 50 vs. 163 ± 41 ms, p = 0.023) were noted. No significant correlations were identified between Yo-Yo IR1 and HRV measures at week 1. In contrast, Yo-Yo IR1 performance was significantly correlated with SDNN (r =0.89, p=0.007) and SD2 (0.92, p=0.003) at week 8. Greater values in HRV at week 1 were substantially associated with lower HRV changes at the end of pre-season (r values ranged from -0.79 to -0.98, p< 0.05). Furthermore, HRV changes were significantly correlated with decreases in HRmax during the pre-season (r values from 0.83 to 0.94, p<0.05). Conclusions: The current results confirm that despite minimal changes in specific fitness (i.e. Yo-Yo IR1), pre-season training significantly improved various HRV indices in elite soccer players with greater changes evident for those with lower initial HRV levels. Nocturnal HRV may provide an important monitoring tool for identification of cardiovascular function changes in top-class soccer players during pre-season regimes.

Vitamin D status in female endurance runners based in the United Kingdom

BACKGROUND: Poor lower limb stability during dynamic movement is thought to increase the risk of musculoskeletal injury. Biomechanically, stability is determined by a number of factors including the external load and contributions from passive and active tissues. One approach for studying lower limb stability is the single leg squat (SLS) test, which requires coordinated lower limb movement across a range of joint motions under external load. Although clinicians typically assess SLS quality from a single point of view (i.e. frontal plane), a 3D investigation of SLS kinematics would help to determine factors that differentiate clinician-defined “good” from “poor” quality performance. PURPOSE: To determine the kinematic parameters that characterise a good or a poor SLS performance in young adults. METHODS: 22 healthy young adults (13 male, 9 female; age: 23.8 ±3.1 years; height: 1.73 ±0.07 m; mass: 69.4 ±12.7 kg) free from musculoskeletal impairment were recruited. Video footage was collected in the frontal plane as participants performed three SLSs on each leg. SLS quality was assessed by a panel of physiotherapists using a ten-point ordinal scale. Performances were subsequently divided into tertiles corresponding to poor, intermediate and good SLS technique. 3D trajectories of 28 reflective markers attached to the pelvis, and lower limbs were simultaneously recorded at 200 Hz using a 10-camera, motion capture system (Vicon Motion Systems, Oxford, UK). Pelvis, hip and knee angles were calculated using a validated lower limb biomechanical model that incorporated functional identification of hip and knee joint centres. RESULTS: Mean rating of SLS quality as assessed by the panel of physiotherapists was 6.3±1.9 (range: 2.4 - 9.1). 3D analysis of SLS performance revealed that poor squatters had increased hip adduction (22.4 ±6.1 vs 14.7 ±4.7 deg, p<0.01), reduced knee flexion (73.1 ±8.7 vs 90.1 ±12.1 deg, p<0.01) and increased medal-lateral displacement of the knee joint centre (53.7 ±16.8 vs 38.4 ±14.3 mm, p=0.02) compared to good squatters. CONCLUSION: In healthy young adults a poor SLS is characterised by inadequate knee flexion and excessive frontal plane motion at the knee and hip. It is recommended that clinicians standardise knee flexion angle when using the SLS test as it might confound the perception of SLS quality.Purpose: To evaluate changes in performance and cardiac autonomic control (i.e. heart rate [HR] variability [HRV]) in elite soccer players during their pre-season training regime. Methods: Eight Spanish Premier League soccer players were examined at the first (week 1) and the last week (week 8) of the pre-season period (July-September). Nocturnal HR recordings on 4 days per week were averaged to evaluate the weekly HRV. Players also completed the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) for the assessment of specific fitness. Results: During the pre-season period, there was no significant change (4.5 ± 23.9%) in Yo-Yo IR1 performance (2,475 ± 421 vs. 2,600 ± 786 m, p=0.55), while there was a significant decrement (6.3 ± 4.3%) in maximal HR (HRmax) recorded during the test (191 ± 7 vs. 179 ± 8 bpm, p = 0.004). Over the 8-week pre-season, significant increases in the standard deviation of the long-term continuous HRV (SD2) (174 ± 56 vs. 212 ± 53 ms, p = 0.017), and in the standard deviation of all HR intervals (SDNN) (135 ± 50 vs. 163 ± 41 ms, p = 0.023) were noted. No significant correlations were identified between Yo-Yo IR1 and HRV measures at week 1. In contrast, Yo-Yo IR1 performance was significantly correlated with SDNN (r =0.89, p=0.007) and SD2 (0.92, p=0.003) at week 8. Greater values in HRV at week 1 were substantially associated with lower HRV changes at the end of pre-season (r values ranged from -0.79 to -0.98, p< 0.05). Furthermore, HRV changes were significantly correlated with decreases in HRmax during the pre-season (r values from 0.83 to 0.94, p<0.05). Conclusions: The current results confirm that despite minimal changes in specific fitness (i.e. Yo-Yo IR1), pre-season training significantly improved various HRV indices in elite soccer players with greater changes evident for those with lower initial HRV levels. Nocturnal HRV may provide an important monitoring tool for identification of cardiovascular function changes in top-class soccer players during pre-season regimes.

Non-malignant lytic lesions of bone.

Dear Editor, We report on the case of an 80-year-old woman with widespread lytic lesions throughout her skeleton which despite initial appearances were found to be non-malignant. The patient was admitted to the Rheumatology Department, Royal Derby Hospital, UK, with a 1month history of left knee pain and swelling which had become worse the previous day following a fall. For the preceding 3 years she had been undergoing monthly transfusions for myelofibrosis. Calcium pyrophosphate crystals were visualised on microscopy of knee aspirate. Pelvic X-ray, taken to exclude hip fracture, showed widespread small lytic lesions as well as two large cystic areas within the left proximal femur with cortical scalloping, although no fracture was present. The appearances were considered to be consistent with myeloma or metastases. Routine blood tests including calcium and alkaline phosphatase were unremarkable, protein electrophoresis and free light chain ratio were normal and chest X-ray showed no abnormality. All standard tumor markers were negative and a mammogram was normal. A computed tomography scan of chest, abdomen and pelvis was performed which detected focal discrete lytic lesions throughout the skeleton, on a background of osteosclerosis in keeping with her diagnosis of myelofibrosis (Fig. 1). A nuclear medicine bone scan demonstrated linear focal increased uptake in both the proximal left femoral diaphysis and the proximal right humerus, consistent with pathological fractures. Plain X-ray showed no fracture at either site. Following hematology review she underwent bone marrow aspiration and trephine. Histological examination of this demonstrated only grade IV myelofibrosis. There was no evidence of metastases. Given the severity of myelofibrosis demonstrated it was felt this could explain her widespread skeletal lucencies. The patient underwent prophylactic gamma nailing of a large lucency in her left femur. Bone biopsy of the site confirmed the absence of metastases. She was discharged with hematological follow-up. Myelofibrosis is a myeloproliferative disorder resulting in fibrotic replacement of the bone marrow, and the finding of discrete lytic lesions in patients with this as a sole diagnosis is extremely uncommon. Two studies published in the late 1950s to early 1960s documented the clinical and pathological findings in patients with myelofibrosis. The first looked at 110 patients with a primary diagnosis of myelofibrosis, excluding those with known malignancy. The X-ray films of these patients revealed mainly focal osteosclerotic changes, although normal findings or those of generalised increased density were also seen. The second, published in 1959, looked at 25 patients seen Figure 1 X-ray and computed tomography images of the patient’s pelvis. Arrows indicate multiple lytic lesions. International Journal of Rheumatic Diseases 2012; 15: e10–e11