Fracture definitions in observational osteoporosis drug effects studies that leverage healthcare administrative (claims) data: a scoping review.

Healthcare administrative (claims) data are commonly utilized to estimate drug effects. We identified considerable heterogeneity in fracture outcome definitions in a scoping review of 57 studies that estimated osteoporosis drug effects on fracture risk. Better understanding of the impact of different fracture definitions on study results is needed. PURPOSE: Healthcare administrative (claims) data are frequently used to estimate the real-world effects of drugs. Fracture incidence is a common outcome of osteoporosis drug studies. We aimed to describe how fractures are defined in studies that use claims data. METHODS: We searched MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), and gray literature for studies published in English between 2000 and 2020 that estimated fracture effectiveness (hip, humerus, radius/ulna, vertebra) or safety (atypical fracture of the femur, AFF) of osteoporosis drugs using claims data in Canada and the USA. Literature searches, screening and data abstraction were completed independently by two reviewers. RESULTS: We identified 57 eligible studies (52 effectiveness, 3 safety, 2 both). Hip fracture was the most common fracture site studied (93%), followed by humerus (66%), radius/ulna (59%), vertebra (61%), and AFF (9%). Half (n = 29) of the studies did not indicate specific data sources, codes, or cite a validation paper. Of the papers with sufficient detail, heterogeneity in fracture definitions was common. The most common definition within each fracture site was used by less than half of the studies that examined effectiveness (12 definitions in 29 hip fracture papers, 8 definitions in 17 humerus papers, 8 definitions in 13 radius/ulna papers, 9 definitions in 15 vertebra papers), and 3 definitions among 4 AFF papers. CONCLUSION: There is ambiguity and heterogeneity in fracture outcome definitions in studies that leverage claims data. Better transparency in outcome reporting is needed. Future exploration of how fracture definitions impact study results is warranted.

Osteoporosis case ascertainment strategies in European and Asian countries: a comparative review.

While many clinical guidelines recommend screening for osteoporosis for early detection and treatment, there is great diversity in the case-finding strategies globally. We sought to compare case-finding strategies, focusing on the approaches used in European and Asian countries. This article provides an overview of the current case-finding strategies in the UK, Germany (including Austria and German-speaking regions of Switzerland), China, Japan, and Korea. We conducted a review of current treatment guidelines in each country and included expert opinions from key opinion leaders. Most countries define osteoporosis among patients with a radiographically identified fracture of the hip or the vertebrae. However, for other types of fractures, or in the absence of a fracture, varying combinations of risk-factor assessment and areal bone mineral density (aBMD) assessed by dual X-ray absorptiometry are used to define osteoporosis cases. A T-score ≤ - 2.5 is accepted to identify osteoporosis in the absence of a fracture; however, not all countries accept DXA alone as the sole criteria. Additionally, the critera for requiring clinical risk factors in addition to aBMD differ across countries. In most Asian countries, aBMD scanning is only provided beyond a particular age threshold. However, all guidelines recommend fracture risk assessment in younger ages if risk factors are present. Our review identified that strategies for case-finding differ regionally, particularly among patients without a fracture. More homogenized ways of identifying osteoporosis cases are needed, in both the Eastern and the Western countries, to improve osteoporosis case-finding before a fracture occurs.Case-finding in osteoporosis is essential to initiate treatment and minimize fracture risk. We identified differences in case-finding strategies between Eastern and Western countries. In the absence of a diagnosed fracture, varying combinations of risk factors and bone density measurements are used. Standardized case-finding strategies may help improve treatment rates.

Fracture Patterns in Type 1 and Type 2 Diabetes Mellitus: A Narrative Review of Recent Literature.

PURPOSE OF REVIEW: In this narrative review, we have summarized the literature on fracture risk in T1DM and T2DM with a special focus on fracture site, time patterns, glucose-lowering drugs, and micro- and macrovascular complications. RECENT FINDINGS: T1DM and T2DM were associated with an overall increased fracture risk, with preferent locations at the hip, vertebrae, humerus, and ankle in T1DM and at the hip, vertebrae, and likely humerus, distal forearm, and foot in T2DM. Fracture risk was higher with longer diabetes duration and the presence of micro- and macrovascular complications. In T2DM, fracture risk was higher with use of insulin, sulfonylurea, and thiazolidinediones and lower with metformin use. The increased fracture risk in T1DM and T2DM concerns specific fracture sites, and is higher in subjects with longer diabetes duration, vascular complications, and in T2DM with the use of specific glucose-lowering medication.

Time trends in oral bisphosphonate initiation in Ontario, Canada over 20 years reflect drug policy and healthcare delivery changes.

Characteristics of patients starting oral bisphosphonate therapy changed over time, reflecting trends in osteoporosis management (e.g., new drugs to market), and general healthcare delivery (e.g., benzodiazepine use declined, statin use increased). When designing studies that examine osteoporosis drug effects, potential time-related biases must be considered. INTRODUCTION: To describe the type of oral bisphosphonate initiated and characteristics of patients starting oral bisphosphonate therapy over time. METHODS: We identified community-dwelling older adults (ages ≥ 66 years) initiating oral bisphosphonate therapy from April 1996 to March 2016 (1996 to 2015 fiscal years) using healthcare administrative data in Ontario. Patients with conditions other than osteoporosis that may impact bisphosphonate prescribing were excluded. The bisphosphonate initiated and patient characteristics were summarized by fiscal year and stratified by sex. RESULTS: We identified 560,817 eligible patients (81% women). Most patients initiated cyclical etidronate from 1996 until 2005, and then weekly regimens became dominant. In 2008, risedronate became the main oral bisphosphonate (46% risedronate, 43% alendronate, 11% etidronate); with its use increasing after availability of monthly and delayed-release risedronate formulations. In 2015, 71% of patients started risedronate, 28% started alendronate, and less than 2% started etidronate. Characteristics of patients changed over time, reflecting changes in osteoporosis management and general healthcare delivery. Over time, a larger proportion of men (9% to 28%) and patients with diabetes (women 10% to 17%, men 14% to 22%) initiated therapy; benzodiazepine (women 22% to 13%, men 20% to 10%) and estrogen-based hormone replacement therapy (12% to 15% of women 1996-2002 to 3% since 2008) decreased, while statin use increased (women 15% to 39%, men 14% to 52%). CONCLUSIONS: The characteristics of patients starting oral bisphosphonate therapy have changed over time. Consideration must be given to these time trends when designing studies that examine osteoporosis drug effects.

Association between use of antidepressants or benzodiazepines and the risk of subsequent fracture among those aged 65+ in the Netherlands.

This is the first study to examine the association between antidepressant and benzodiazepine use following a MOF and risk of subsequent fracture in those 65+. Using national data, drug use following MOF showed that the 1-year fully adjusted risk of subsequent MOF in those on antidepressants was more than doubled. INTRODUCTION: We evaluated the association between the use of antidepressants or benzodiazepines and the risk of a subsequent major osteoporotic fracture. METHODS: A cohort study was performed using the Dutch PHARMO Database Network. Between 2002 and 2011, a total of 4854 patients sustained a first major osteoporotic fracture after the age of 65 years, of which 1766 sustained a hip fracture. Incidence rates and adjusted hazard ratios were calculated using Cox proportional hazards models. RESULTS: Within 1 year following a major osteoporotic fracture, 15% (95% CI 13.7-15.7) and 31% (95% CI 30.1-32.8) of patients were dispensed an antidepressant or benzodiazepine, respectively. Current use of antidepressants in the first year following a major osteoporotic fracture was associated with subsequent fracture (adjusted HR 2.17 (95% CI 1.37-3.43)). Recent and past use of antidepressants were also associated with an increased risk of subsequent fracture. When the complete follow-up period was included, only the current use of antidepressants was associated with subsequent fracture following a major osteoporotic fracture (adjusted HR 1.48; 95% CI 1.06-2.06). Current benzodiazepine use was not associated with an increased risk of fracture within 1 year following a major osteoporotic fracture (adjusted HR 1.18; 95% CI 0.76-1.81) or during the complete follow-up period (adjusted HR 1.18; 95% CI 0.90-1.55). CONCLUSION: This study provides evidence that antidepressants should be used with caution following a major osteoporotic fracture. It provides needed insights that can be used to inform clinicians when assessing subsequent fracture risk in patients.

Uptake and characteristics of zoledronic acid and denosumab patients and physicians in Ontario, Canada: impact of drug formulary access.

UNLABELLED: The addition of Limited Use criteria (less restrictive access) for zoledronic acid resulted in an immediate and significant increase in uptake and resulted in differences in patient/physician characteristics. In comparison, the uptake of denosumab (only listed with Limited Use) was rapid. Thus, formulary access restrictions have significant implications for prescribing. INTRODUCTION: We sought to describe the use of zoledronic acid and denosumab by physicians and patients over time and examine the impact of a 2012 provincial formulary modification that removed the administrative burden on physicians when prescribing zoledronic acid. METHODS: We identified users of zoledronic acid and denosumab using Ontario pharmacy claims data. The number of new patients and physicians was plotted and examined over time. Interrupted time series analysis examined the impact of a formulary modification to zoledronic acid use and prescribing. Descriptive characteristics of patients and prescribers were summarized pre- and post-formulary modification for zoledronic acid and overall for denosumab. RESULTS: We identified 1463 zoledronic acid patients treated by 627 physicians and 16,736 denosumab patients treated by 2904 physicians. In the first 2 months on the market, we identified a rapid uptake of denosumab (>450 physicians and >1200 patients) in contrast to zoledronic acid (<10 physicians and <10 patients). Zoledronic acid use increased significantly in the 2-month post-formulary change, yet no change in denosumab was observed. Prior to the formulary modification, more zoledronic acid patients had a history of osteoporosis therapy (41 vs. 26%) or bone density testing (30 vs. 10%). Compared to zoledronic patients (post-formulary modification), more denosumab patients had prior osteoporosis therapy (55 vs. 26%), yet fewer had a gastrointestinal diagnosis (6 vs. 11%). CONCLUSION: We identified a rapid uptake of denosumab in only 15 months of observation. A provincial formulary modification to zoledronic acid resulted in an increase in utilization and impacted patient characteristics.

Long-term persistence with anti-osteoporosis drugs after fracture.

UNLABELLED: Long-term persistence with anti-osteoporosis drugs and determinants for discontinuation among fracture patients were examined. Persistence was 75.0 and 45.3 % after 1 and 5 years, respectively. Those aged ≥80 years were at increased risk of early discontinuation. Within 1 year after discontinuation, 24.3 % restarted therapy, yet 47.0 % persisted for 1 year. INTRODUCTION: The risk of osteoporotic fracture can effectively be reduced with use of anti-osteoporosis drugs. However, little is known about persistence with these drugs after fracture where subsequent fracture risk is high. The aims were to determine long-term persistence with anti-osteoporosis drugs among fracture patients, including its determinants, and to describe restart and subsequent persistence. METHODS: A cohort study was conducted within the Dutch PHARMO Database Network. Patients aged ≥50 years (n = 961) who received anti-osteoporosis drugs within 1 year after fracture, but not in the preceding year, were included (2002-2011). Persistence (defined as the proportion on treatment) and the proportion restarting after discontinuation were estimated using Kaplan-Meier analyses. Time-dependent Cox regression was used to identify determinants of non-persistence including age, sex, initial dosage regime, fracture type, comorbidities, and drug use. RESULTS: Persistence with anti-osteoporosis drugs was 75.0 % (95 % confidence interval (CI) 72.0-77.7) and 45.3 % (95 % CI 40.4-50.0) after 1 and 5 years, respectively. A significant determinant of non-persistence was age ≥80 years (reference 50-59 years: adjusted hazard ratio [adj. HR] 1.65; 95 % CI 1.15-2.38). This effect was not constant over time (≤360 days following initiation: adj. HR 2.07; 95 % CI 1.27-3.37; >360 days: adj. HR 1.08; 95 % CI 0.62-1.88). Within 1 year after discontinuation, 24.3 % (95 % CI 20.1-29.2) restarted therapy, yet 47.0 % persisted for 1 year. CONCLUSIONS: This study identified suboptimal persistence with anti-osteoporosis drugs among fracture patients. Major target groups for measures aimed to improve persistence may be those aged >80 years and those restarting therapy.

Can masticatory electromyography be normalised to submaximal bite force?

The combination of bite force and jaw muscle electromyography (EMG) provides an insight into the performance of the stomatognathic system, especially in relation to dynamic movement tasks. Literature has extensively investigated possible methods for normalising EMG data encapsulating many different approaches. However, bite force literature trends towards normalising EMG to a maximal voluntary contraction (MVC), which could be difficult for ageing populations or those with poor dental health or limiting conditions such as temporomandibular disorder. The objectives of this study were to (i) determine whether jaw-closing muscle activity is linearly correlated with incremental submaximal and maximal bite force levels and (ii) assess whether normalising maximal and submaximal muscle activity to that produced when performing a low submaximal bite force (20 N) improves repeatability of EMG values. Thirty healthy adults (15 men, 15 women; mean age 21 ± 1·2 years) had bite force measurements obtained using a custom-made button strain gauge load cell. Masseter and anterior temporalis muscle activities were collected bilaterally using surface EMG sensors whilst participants performed maximal biting and three levels of submaximal biting. Furthermore, a small group (n = 4 females) were retested for reliability purposes. Coefficients of variation and intra-class correlation coefficients showed markedly improved reliability when EMG data were normalised compared to non-normalised. This study shows that jaw muscle EMG may be successfully normalised to a very low bite force. This may open possibilities for comparisons between at-risk sample groups that may otherwise find it difficult to produce maximal bite force values.

Bisphosphonate prescribing, persistence and cumulative exposure in Ontario, Canada.

UNLABELLED: We studied new users of oral bisphosphonates and found that less than half persisted with therapy for 2 years, and interruptions in use were common. During a median observation period of 4.7 years, 10% of patients filled only a single prescription, 37% switched therapies and median cumulative exposure was 2.2 years. INTRODUCTION: We sought to describe bisphosphonate prescribing, persistence and cumulative exposure among seniors in Ontario, Canada. METHODS: We used Ontario Drug Benefit pharmacy claims to identify residents aged ≥ 66 years who initiated oral bisphosphonate therapy between April 1996 and March 2009. The first date of bisphosphonate dispensing was considered the index date. Persistence with therapy was defined as continuous treatment with no interruption exceeding 60 days. We examined persistence with therapy and the number of extended gaps (>60 days) between prescriptions over time periods ranging from 1 to 9 years. We also identified the proportion of patients filling only a single prescription and switching to a different bisphosphonate, and calculated the median days of exposure irrespective of gaps in therapy. RESULTS: A total of 451,113 eligible new bisphosphonate users were identified: mean age = 75.6 years (SD = 6.9), 84% female, and median follow-up length = 4.7 years. Persistence with therapy declined from 63% at 1 year to 46% at 2 years and 12% at 9 years. Among those with at least 5 years of follow-up (n = 213,029), 61% had one or more extended gaps in bisphosphonate therapy. Overall, 10% of patients filled only a single prescription, 37% switched to a different bisphosphonate and the median exposure was 2.2 years. CONCLUSION: Less than half of patients persisted with bisphosphonate therapy for 2 years and interruptions in therapy were common, with most patients experiencing two or more >60-day gaps in therapy. Interventions are needed to improve persistence with bisphosphonate therapy and reduce the frequency of gaps in treatment.

The impact of pharmacist interventions on osteoporosis management: a systematic review.

UNLABELLED: We completed a systematic review of the literature to examine the impact of pharmacist interventions in improving osteoporosis management. Results from randomized controlled trials suggest that pharmacist interventions may improve bone mineral density testing and calcium intake among patients at high risk for osteoporosis. INTRODUCTION: Pharmacists play a key role in many healthcare systems by helping patients manage chronic diseases. We completed a systematic review of the literature to identify randomized controlled trials (RCTs) that have examined the impact of pharmacy interventions in narrowing two gaps in osteoporosis management: identifying at-risk individuals and improving adherence to therapy. METHODS: We searched the electronic databases of EMBASE, HealthStar, International Pharmaceutical Abstracts, MEDLINE, and PubMed from database development to April 2010, examined grey literature, and completed manual searches of reference lists to identify English-language research that examined osteoporosis management interventions within pharmacy practice. Results from RCTs were abstracted and assessed for bias. RESULTS: We identified 25 studies that examined pharmacist interventions in osteoporosis management: 16 cohort, 5 cross-sectional, 1 historical/ecological control, and 3 RCTs. RCT interventions included osteoporosis educational and counseling programs, screening by pharmacists based on risk factor assessment or bone mineral density testing, and physician contact or recommendations for patients to follow-up with a general practitioner. Results from the three RCTs suggest that pharmacist interventions may improve bone mineral density testing (targeted screening) and calcium intake among patients at high risk for osteoporosis. However, two of the three RCTs had high risk of bias, and no study examined the impact of pharmacist intervention on osteoporosis treatment adherence. CONCLUSIONS: Data support the potential role for pharmacists to help reduce gaps in osteoporosis management through improved identification of high-risk patients. More research is needed to examine pharmacist interventions on osteoporosis treatment adherence.

Increased radiographic progression of distal hand osteoarthritis occurring during biologic DMARD monotherapy for concomitant rheumatoid arthritis.

OBJECTIVES: A considerable proportion of patients with rheumatoid arthritis (RA) also suffer from hand osteoarthritis (OA). We here assess the association between conventional synthetic (cs) and biological (b) disease-modifying antirheumatic drugs (DMARDs) and radiographic distal interphalangeal-(DIP) OA in patients with RA. METHODS: Adult RA patients from a longitudinal Swiss registry of rheumatic diseases who had ≥ 2 hand radiographs were included at the first radiograph and followed until the outcome or the last radiograph. Patients were grouped into two cohorts based on whether DIP OA was present or absent at cohort entry (cohorts 1 and 2, respectively). Modified Kellgren-Lawrence scores (KLS) were obtained by evaluating DIP joints for the severity of osteophytes, joint space narrowing, subchondral sclerosis, and erosions. KLS ≥ 2 in ≥ 1 DIP joint indicated incident or existing OA, and increase of ≥ 1 in KLS in ≥ 1 DIP joint indicated progression in existing DIP OA. Time-varying Cox regression and generalized estimating equation (GEE) analyses were performed. We estimated hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CI) of DIP OA incidence (cohort 2), or progression (cohort 1), in bDMARD monotherapy, bDMARD/csDMARD combination therapy, and past or never DMARD use, when compared to csDMARD use. In post hoc analyses, we descriptively and analytically assessed the individual KLS features in cohort 1. RESULTS: Among 2234 RA patients with 5928 radiographs, 1340 patients had DIP OA at baseline (cohort 1). Radiographic progression of DIP OA was characterized by new or progressive osteophyte formation (666, 52.4%), joint space narrowing (379, 27.5%), subchondral sclerosis (238, 17.8%), or erosions (62, 4.3%). bDMARD monotherapy had an increased risk of radiographic DIP OA progression compared to csDMARD monotherapy (adjusted HR 1.34 [95% CI 1.07-1.69]). The risk was not significant in csDMARD/bDMARD combination users (HR 1.12 [95% CI 0.96-1.31]), absent in past DMARD users (HR 0.96 [95% CI 0.66-1.41]), and significantly lower among never DMARD users (HR 0.54 [95% CI 0.33-0.90]). Osteophyte progression (HR 1.74 [95% CI 1.11-2.74]) was the most significantly increased OA feature with bDMARD use compared to csDMARD use. In 894 patients without initial DIP OA (cohort 2), the risk of incident OA did not differ between the treatment groups. The results from GEE analyses corroborated all findings. CONCLUSIONS: These real-world RA cohort data indicate that monotherapy with bDMARDs is associated with increased radiographic progression of existing DIP OA, but not with incident DIP OA.

Stature loss and recovery following a period of loading: effect of time of day and presence or absence of low back pain.

BACKGROUND: Stature reductions in asymptomatic individuals, caused by a set load, are lower later in the day when stature is in the trough of diurnal variation; hence most stature reduction investigations are conducted in the morning. Recent evidence suggests that it is not the reductions in stature, but the recovery of stature, that is of greatest importance. The aim of this investigation was to establish whether stature recovery is also affected by time of day and to determine if any differences exist between a chronic low back pain and asymptomatic group. METHODS: Eleven chronic low back pain participants (age=32.8 SD 7.9 yrs, mass=74.4 SD 14.2 kg and height=1.73 SD 0.07 m) and 11 asymptomatic participants (age=31.0 SD 6.3 yrs, body mass=72.6 SD 11.5 kg and height=1.76 SD 0.09 m) underwent two 20 min loaded walking tasks (10% body mass), one in the morning (09:00) and one in the afternoon (14:00), followed by a 20 min unloaded recovery period. Measurements of stature were obtained throughout. FINDINGS: The asymptomatic group experienced significantly less stature reduction (P=0.05; ES=1.1) and greater stature recovery (P=0.02; ES=0.9) in the afternoon compared to the morning. The chronic low back pain group experienced a similar pattern to the asymptomatic group, however no significant difference between sessions for changes in stature was evident P=0.07. INTERPRETATION: Further investigations of stature recovery should be restricted to the morning when comparing individuals with and without chronic low back pain, as time of day appeared to have effect on stature recovery, particularly in the asymptomatic group. Time dependent differences in stature change between these two populations warrants further investigation.

Impact of detection bias on the risk of gastrointestinal cancer and its subsites in type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) may be a risk factor for gastrointestinal (GI) cancers, but variations in study designs of observational studies may have yielded biased results due to detection bias. Furthermore, differences in risk for GI cancer subsites have not been extensively evaluated. We aimed to determine the risk of GI cancer and its subsites in patients with T2DM and how it is affected by detection bias. METHODS: A matched cohort study was performed using the NCR-PHARMO database. New-users of ≥1 non-insulin anti-diabetic drug during 1998-2011 were matched with non-diabetic controls by year of birth, sex, and time between database entry and index. Cox regression analyses were performed with and without lag-period to estimate hazard ratios (HRs) for GI cancer and its subsites. Covariables included age, sex, use of other drugs and history of hospitalisation. RESULTS: An increased risk of GI cancer was observed in T2DM patients (HR 1.5, 95% confidence interval [CI] 1.3-1.7) compared with controls, which was attenuated in the 1-year lagged analysis (HR 1.4, 95% CI 1.2-1.7). Stratified by subsite, statistically significant increased risks of pancreatic (HR 4.7, 95% CI 3.1-7.2), extrahepatic bile duct (HR 4.2, 95% CI 1.5-11.8) and distal colon cancer (HR 1.5, 95% CI 1.1-2.1) were found, which remained statistically significantly increased in the lagged analysis. CONCLUSIONS: T2DM patients had a 40% increased risk of GI cancer. Increased GI cancer risks tended to be weaker when reducing detection bias by applying a 1-year lag-period. Future observational studies should therefore include sensitivity analyses in which this bias is minimised.

The influence of different unloading positions upon stature recovery and paraspinal muscle activity.

OBJECTIVE: To determine whether stature recovery and paraspinal muscle activity can be altered in individuals with and without chronic low-back pain by assuming different unloading positions. DESIGN: A case-control study considering the effects of unloading position on stature recovery in individuals with and without chronic low-back pain. BACKGROUND: Stature recovery has been documented to be lower in individuals with chronic low-back pain. Elevated paraspinal muscle activity subjects the spine to increased compression, which may delay stature recovery. However, the mechanism(s) causing prolonged stature recovery are yet to be explored. METHODS: Eleven chronic low-back pain participants (age 33 yr (SD 12.2), height 1.72 m (SD 0.08), body mass 75.9 kg (SD 10.7)) and eleven asymptomatic participants (age 30.5 yr (SD 9.7), height 1.75 m (SD 0.10), body mass 73.3 kg (SD 11.7)) performed a loaded walking task (10% body mass) and adopted four unloading positions on separate occasions. Measurements of stature and muscle activity were recorded during each position. FINDINGS: Individuals with chronic low-back pain exhibited higher paraspinal EMG and delayed stature recovery in all positions (P<0.05). Both groups experienced greatest stature recovery and least muscle activity during gravity inversion (P<0.05). INTERPRETATION: Elevated muscle activity was found in the chronic low-back pain group supporting the existence of this explanation for delayed stature recovery. The gravity inverted position resulted in the lowest EMG and the greatest stature recovery. Further research is required to determine whether improving stature recovery has clinical implications by reducing pain/disability.

Case report: reduction of low back pain in a professional golfer.

Previous research agrees that the majority of injuries that affect male golfers are located in the lower back and that they are related to improper swing mechanics and/or the repetitive nature of the swing. This study describes the trunk motion and paraspinal muscle activity during the swing of a golfer with related low back pain (LBP) and assesses the effect of a 3-month period of muscle conditioning and coaching on these variables. Motion of the trunk was measured using three-dimensional video analysis and electromyograms (EMGs) were recorded from the same six sites of the erector spinae at the start and end of the 3-month period. At the end of the period, the golfer was able to play and practice without LBP. Coaching resulted in an increase in the range of hip turn and a decrease in the amount of shoulder turn, which occurred during the swing. In addition, a reduction in the amount of trunk flexion/lateral flexion during the downswing occurred in conjunction with less activity in the left erector spinae. These changes may serve to reduce the torsional and compressive loads acting on the thoracic and lumbar spine, which in turn may have contributed to the cessation of the LBP and would reduce the risk of reoccurrence in the future. In conclusion, further research with more subjects would now be warranted in order to test the findings of this program for the prevention of low back in golfers as piloted in this case report.

Normalisation of gait EMGs: a re-examination.

The purpose of this study was to compare four different methods of normalising electromyograms (EMGs) recorded during normal gait. Comparisons were made between the amplitude, intra-individual variability and inter-individual variability of EMGs. Surface EMGs were recorded from the biceps femoris, semitendinosus, vastus lateralis and vastus medialis of ten males and two females while they walked on a treadmill at a self-selected speed. EMGs from the same muscles were subsequently recorded during isometric maximal voluntary contractions (MVCs) and concentric, isokinetic MVCs that were performed between 0.52 and 7.85 rad x s(-1) on a BIODEX dynamometer. EMGs were also recorded during eccentric, isokinetic MVCs between 0.52 and 2.62 rad x s(-1). Gait EMGs were then normalised at 2% intervals of the gait cycle by expressing them as a percentage of the following reference values: the mean (mean dynamic method) and the peak (peak dynamic method) EMG from the intra-individual ensemble average; the EMG from an isometric MVC (isometric MVC method); and the EMG from an isokinetic MVC that occurred with the same muscle action, length and velocity of musculotendinous unit as the gait EMGs (isokinetic MVC method). The isokinetic MVC method produced significantly greater (P<0.05) intra-individual variability compared to the other methods when it was measured using the variance ratio. Inter-individual variability of gait EMGs, again measured using the variance ratio, was also greatest when they were normalised using the isokinetic MVC method. The pattern and amplitude of EMGs normalised using the isometric MVC method and the isokinetic MVC method were very similar (root mean square difference and absolute difference both less than 3%). It was concluded that the isokinetic MVC method should not be adopted by gait researchers or clinicians as it does not reduce intra- or inter-individual variability anymore than existing normalisation methods, nor does it provide a more representative measure of muscle activation during gait than the isometric MVC method.

Validity of weight distribution and sway measurements of the Balance Performance Monitor.

BACKGROUND AND PURPOSE: The Balance Performance Monitor (BPM) is a device which provides auditory and visual feedback on weight distribution and the magnitude of lateral and anterior-posterior sway during quiet standing. This study investigated the validity of the measurements provided by the BPM using a Kistler force plate (KFP) as the gold standard. METHOD: Percentage weight distribution between the BPM foot plates was validated using both a series of calibration weights and the vertical component of ground reaction force, measured by the KFP, during normal standing in 18 young normal subjects. The lateral and anterior-posterior sway indices from the BPM were validated against the standard deviation of the position of the centre of pressure, again obtained using the KFP, during normal standing with eyes open and eyes closed and standing with feet together with eyes open. Concurrent validity of the percentage weight distribution measurements was assessed by calculating the 'limits of agreement' between the corresponding measurements from the BPM and KFP and the 95% confidence intervals for these 'limits'. Differences in the units of measurement obtained from the BPM and KFP resulted in the concurrent validity of the sway indices being assessed using correlation and regression. RESULTS: Excellent agreement was found between the percentage weight distribution values provided by the BPM and the KFP, which showed that the BPM may read only 3% of body weight above or below that given by the KFP. High correlations (r = 0.61-0.99) were found between both the lateral and anterior-posterior sway indices from the BPM and the motion of the centre of pressure from the KFP in the respective direction. Despite this, further analysis of regression equations and the 95% prediction intervals showed poor concurrent validity of the BPM sway indices in relation to KFP measurements. This was thought to be due to the different methods by which the sway indices and the motion of the centre of pressure were calculated. CONCLUSIONS: The BPM may be used to provide a valid measure of the symmetry aspect, but not necessarily the steadiness aspect of postural control.

Loads on the lumbar spine during a work capacity assessment test.

Many clinicians and employers utilise work-related assessment tools for the purposes of identifying whether or not the performance of a specific job exposes an individual to a heightened risk of developing a low back injury. However, research has shown that some of these tools have not been assessed for validity or reliability, and thus may not accurately assess the risk associated with a particular activity. An example of a test employed by some Australian private industries is the Work Capacity Assessment Test, which is a procedure that is commonly used to screen potential employees and evaluate those workers returning to the workplace following injury. This research was designed to simulate the lifting component of the Work Capacity Assessment Test and involved a series of lifts ranging from 2.5 kg to 22.5 kg. Six subjects performed this task, whilst being assessed using two-dimensional videography and surface electromyography. The two-dimensional kinematic data were input into the 4D WATBAK software to quantify the compression forces acting between L4 and L5 during each performance. Results of this study showed that spinal compression and paraspinal muscle activity increased incrementally from the 2.5 kg lift to the 22.5 kg lift, whilst abdominal muscle activity also increased across the lifts. This study demonstrated that lifting masses of 22.5 kg or more can produce loads on the spine that are considered potentially hazardous, when compared to safe lifting guidelines, and indicated that there is a clear concern for the use of such lifting tasks in the evaluation of workers following injury.

Repeatability of stature measurements in individuals with and without chronic low-back pain.

Measurements of reduction in stature have been used to compare spinal loading in chronic low-back pain (CLBP) and asymptomatic populations. Whether there are any differences in the repeatability of stature measurements, between those with and without CLBP, is not known. This investigation aimed to determine the repeatability of stature measurements in those with (n = 12) and without (n = 12) CLBP, and to establish if the ability to produce repeatable measurements is retained after a specific timeframe. Stature measurements were taken on two separate sessions that were 2 weeks apart, using a stadiometer accurate to 0.01 mm. All participants attained a mean SD of < or = 0.5 mm by the third measurement set taken on the first session of testing and no significant difference in mean SD was found between those with (0.37 mm) and without (0.40 mm) CLBP (p > 0.05). Intraclass correlation coefficients (ICC) demonstrated good levels of repeatability for all stature measurements obtained from the participants and the values for Standard error of the measurement (SEM) improved as the mean SD decreased with each measurement set. Investigators should have confidence in the ability of those with and without CLBP to produce equally repeatable stature measurements with appropriate prior practice. The second session of testing demonstrated that both groups had retained the ability to achieve the desired level of repeatability (SD < or = 0.5 mm) 2 weeks later without further practice.

Hip and shoulder rotations during the golf swing of sub-10 handicap players.

The motion of the shoulders, arms and club during the golf swing has often been explained using the 'double pendulum' model. Despite subsequent explanations for the actions of the distal segments of the body, the coordination of more proximal segments during the swing is less well understood. To ascertain the pattern of centre of mass motion and hip and shoulder rotations that result in a high clubhead speed at impact, the swing used in driving from the tee of eight low-handicap golfers was videotaped and analysed using three-dimensional techniques. The shoulders rotated in excess of 90 degrees during the backswing and, in 75% of the golfers, continued rotating away from the flag as the hips began turning back towards it. This sequential pattern of hip and shoulder rotation indicated that they conformed to the 'summation of speed' principle, which is hypothesized to result in a greater torque being applied to the club before impact. The speed of the drive was also benefited by the centre of mass shifting exclusively in the intended direction of ball flight during impact.