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Context: Lower back pain is prevalent in horse riders as a result of the absorption of repetitive and multiplanar propulsive forces from the horse. Global positioning system technology provides potential for in vivo measurement of planar loading during riding. Objective: To quantify the uniaxial loading at the lumbar and cervicothoracic spine during dressage elements. Design: Repeated measures, randomized order. Setting: Equestrian arena. Patients (or Other Participants): Twenty-one female dressage riders. Intervention(s): Each rider completed walk, rising trot, sitting trot, and canter trials in a randomized order. A global positioning system unit was placed within customized garments at C7 and L5, collecting triaxial accelerometry data at 100 Hz. Outcome Measures: PlayerLoad based on the rate of change of acceleration and calculated in the anteroposterior (AP), mediolateral, and vertical planes during each trial. Results: There was no significant main effect for global positioning system location in the AP (P = .76),mediolateral (P = .88), or vertical (P = .76) planes. There was a significant main effect for pace in all trials (P < .001), with successive elements eliciting significantly greater loading (P ≤ .03) in all planes in the order walk < rising trot < canter < sitting trot. There was a significant placement x element interaction only in the AP plane (P = .03) with AP loading greater at L5 during walk, rising trot, and canter trials, but greater at C7 during sitting trot. Conclusions: The significant main effect for dressage element was indicative of greater pace of the horse, with faster pace activities eliciting greater loading in all planes. In vivo measurement of spinal accelerometry has application in the objective measurement and subsequent management of lumbar load for riders. [ABSTRACT FROM AUTHOR]

The aims of this study were to quantify the effects of spinal mobilization on force production, failure point, and muscle activity of the hamstrings during the Nordic hamstring exercise (NHE), and to explore individual differences in responses. In a replicated randomized crossover trial, 24 asymptomatic, recreationally active men (age [mean ± standard deviation]: 27 ± 6 years; body mass: 82 ± 17 kg; height: 181 ± 8 cm) completed 2 standardized intervention trials (L4/5 zygapophyseal mobilizations) and 2 control trials. The failure point of the NHE was determined with 3D motion capture. Peak force, knee flexor torque, and electromyography (EMG) of the biceps femoris were measured. Data analyses were undertaken to quantify mean intervention response and explore any individual response heterogeneity. Mean (95% confidence interval) left-limb force was higher in intervention than in control trials by 18.7 (4.6-32) N. Similarly, right-limb force was higher by 22.0 (3.4-40.6) N, left peak torque by 0.14 (0.06-0.22) N • m, and right peak torque by 0.14 (0.05-0.23) N • m/kg. Downward force angle was decreased in intervention vs control trials by 4.1° (0.5°-7.6°) on the side of application. Both peak EMG activity (P =.002), and EMG at the downward force (right; P =.020) increased in the intervention condition by 16.8 (7.1-26.4) and 8.8 (1.5-16.1) mV, respectively. Mean downward acceleration angle changed by only 0.3° (−8.9° to 9.4°) in intervention vs control trials. A clear response heterogeneity was indicated only for right force (Participant × Intervention interaction: P =.044; response heterogeneity standard deviation = 34.5 [5.7-48.4] N). Individual response heterogeneity was small for all other outcomes. After spinal mobilization, immediate changes in bilateral hamstring force production and peak torque occurred during the NHE. The effect on the NHE failure point was unclear. Electromyographic activity increased on the ipsilateral side. Response heterogeneity was generally similar to the random trial-to-trial variability inherent in the measurement of the outcomes. [ABSTRACT FROM AUTHOR]

Objective: We aimed to compare the post-intervention time-course changes in active knee extension (AKE) and active lumbar flexion (ALF) range of motion in response to unilateral posterior–anterior (UPA) mobilizations of the lumbar spine (L4/5 zygapophyseal). Methods: Twenty-four asymptomatic participants (maleness: 0.58, age [mean ± standard deviation]: 32 ± 8 years, body mass index 25.9 ± 2.6 kg m2) were recruited to a fully controlled crossover trial. Following either the intervention (L4/5 zygapophyseal mobilizations) or control, participants immediately performed the AKE and ALF tests, which were also performed at baseline. Subsequent tests were made at intervals of 5, 10, 15, 20, 25, 30, 45 and 60 min. Results: After adjustment for baseline (mean AKE: 37.2° from full extension, mean ALF: 14.37 cm), sex and age, UPA lumbar mobilizations had a most likely moderate effect on AKE (9.8° closer to full extension; ±1.9) and a likely moderate effect on ALF (1.34 cm; ±90% confidence limits 0.43). The magnitude of the AKE effect became most likely small 20-min posttreatment (5.3; ±1.7) and possibly small/possibly trivial 60-min posttreatment (2.1; ±1.4). For ALF, the magnitude of the effect became most likely small 15-min posttreatment (0.76; ±0.25), possibly small/possibly trivial 25-min posttreatment (0.38; ±0.18) and likely trivial 60-min posttreatment (0.26; ±1.8). Discussion: UPA lumbar mobilizations increased lumbar Range of Motion and hamstring extensibility by a moderate magnitude, with the effect reducing after 10–20-min posttreatment. Clinicians should consider these time-course changes when applying UPA lumbar mobilizations. Clinical Trials Registry: NCT03273400 Evidence Level: 2b [ABSTRACT FROM AUTHOR]

Summary: Objective: Measuring continuous lumbar spine motion in vivo and in vitro could advance our understanding of instability, for example accurately and reliably measuring translation in the sagittal plane may help in the management of spondylolisthesis. The Anglo-European College of Chiropractic (AECC) has developed a method of measuring in vivo continuous inter-vertebral motion in the spine using fluoroscopy and image processing – a method called OSMIA (objective spinal motion imaging assessment). This method can measure both inter-vertebral rotation and translation; however it is unknown how accurate and repeatable this method is for translation in the sagittal plane. This study has been performed to determine the accuracy in vitro and repeatability in vivo of the measurement of inter-vertebral translation using OSMIA. Design: Prospective in vitro accuracy and retrospective in vivo repeatability study. Setting: Anglo-European College of Chiropractic, United Kingdom. Subjects: Continuous lumbar fluoroscopic sequences in vivo were obtained from 10 patients (mean age 38 years, SD 10.2, 42% male) who had previously undergone OSMIA scans using a passive recumbent protocol which negated the action of muscle and motor control on inter-vertebral motion. Methods: For accuracy, calibration model images of the lumbar spine with zero translation were acquired and others’ imaged with digital fluoroscopy at 15Hz during continuous flexion and extension. For inter-examiner repeatability, two observers blinded to each other''s results analysed 10 in vivo lumbar spine fluoroscopy flexion and extension motion sequences for range of translation using automated tracking algorithms. For intra-examiner repeatability, one observer performed the analysis twice. Accuracy was calculated as the root-mean-square (RMS) difference between the known calibration model characteristics and the results acquired from the fluoroscopic sequences. Repeatability was calculated as agreement by standard errors of measurement (SEM) and 95% limits of agreement and reliability by intra class correlation coefficients (ICC) for each inter-vertebral level (L2-S1) from the in vivo motion sequences. Results: The RMS error in measuring translation against the reference standard was under 0.8mm in respect to a standard lumbar vertebra of 35mm depth. With the exception of L5-S1 extension, the SEMs from the in vivo agreement studies were below 0.5mm for all levels and directions (flexion–extension), and for reliability the ICCs were above 0.84. Conclusions: OSMIA successfully measures inter-vertebral translation in vivo and in vitro in passive recumbent motion of the lumbar spine with greater repeatability and accuracy than previously reported studies using fluoroscopy. [Copyright &y& Elsevier]

Background: Moderate alcohol consumption has been shown to be positively associated with increased bone mineral density (BMD). However, other lifestyle choices have also been shown to have an effect on bone health. Objective: The objective was to examine the association between alcohol intake and BMD in women around menopause in the United Kingdom and to determine whether any association is independent of other lifestyle choices. Design: A cross-sectional study design was used to examine the relation between alcohol intake and BMD in a cohort of 3218 women aged 50-62 y from the Aberdeen Prospective Osteoporosis Screening Study. Women were grouped into clusters according to their lifestyle choices. ANCOVA was used to examine the effect of categorized alcohol intake on BMD adjusted for cluster of lifestyle and other baseline covariates. The ANCOVA was repeated for different types of alcoholic beverage (eg, beer, liquor, and wine) separately. Results: Three lifestyle clusters were identified and were based on different levels of the following 3 factors: smoking pack-years, fruit and vegetable intakes, and physical activity. In the lifestyle-adjusted models, women who consumed >1 drink/d of alcohol had a significantly greater femoral neck BMD (P = 0.008) and lumbar spine BMD (P = 0.007) than did those who never consumed alcohol. For separate alcoholic drinks, only beer had a positive significant effect on lumbar spine BMD after adjustment for lifestyle (P = 0.005). Conclusion: Moderate alcohol intake appears to be positively associated with BMD independently of the type of lifestyle led by women around menopause. [ABSTRACT FROM AUTHOR]

In this study, VDR gene ApaI (rs7975232), BsmI (rs 1544410) and TaqI (rs731236) genotypes were compared in men with osteoporosis and male controls. Osteoporosis affects around 20% of all men and overall mortality in the first year after hip fracture is significantly higher in men than women, yet the genetic basis of osteoporosis is less well studied in males. This study consisted of White British males; 69 osteoporosis patients and 122 controls. BMDs at the lumbar spine (vertebrae L1-L4) and hip (femur neck) were measured by dual-energy X-ray absorptiometry (DEXA). The VDR gene ApaI , BsmI and TaqI genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and association analysis was carried out at genotype and haplotype level. Our study suggests that TaqI polymorphism CC genotype frequency is lower in controls and further analysis of genotypes and BMD revealed a significant effect of TaqI polymorphism on Lumbar spine BMD. Two haplotypes (GCC and AAT) were associated with increased osteoporosis risk. In conclusion, VDR gene TaqI polymorphism in recessive mode had a significant effect on lumbar spine BMD within our study. Haplotypes GCC and AAT increase the risk of osteoporosis among White British males.

There are few data concerning the occurrence of peak bone mass in women of South Asian origin. The aim of this study was to determine the level of peak bone mass in South Asian women in the UK and to determine whether any observed differences could be explained by differences in body size. Two groups of South Asian women, those of (1) Pakistani Muslim and (2) Gujarati Hindu origin, together with a European group aged 18 to 36 years, were recruited from primary-care population age-sex registers in the Greater Manchester area. They were invited to attend for a detailed interview-assisted lifestyle questionnaire and assessment of height and weight. Bone mass density (BMD) at the hip and lumbar spine was measured by dual energy X-ray absorptiometry (DEXA) scan (Hologic QDR 4500). Volumetric bone density was measured at the distal radius using pQCT (Norland Stratec XCT 2000). Linear regression was used to determine whether any observed differences in the level of bone mass could be explained by differences in body size. A total of 119 European women with a mean age of 30.4 years, 98 Pakistani Muslim women with a mean age of 29.2 years and 20 Gujarati Hindu women with a mean age of 29.2 years had bone density measurements performed. The Europeans were taller and heavier than either South Asian group. Peak BMD was greater among the European than the Pakistani women at all three measuring sites, with the Gujarati women having intermediate values at the hip and lumbar spine. Observed differences disappeared, however, after adjusting for height and weight. There were no differences in volumetric density at the lumbar spine or distal radius between the groups. In summary, there are differences in the level of bone mass between European and South Asian women, though these can be explained by differences in bone size, height or weight.