Arthur Mallinson

Knee Extension Strength Is a Significant Determinant of Static and Dynamic Balance as Well as Quality of Life in Older Community-Dwelling Women with Osteoporosis

Background: Determinants of balance have not been well studied in women with osteoporosis yet falls are the major cause of fracture in this population. Objective: To describe the associations among knee extension strength, medication history, medical history, physical activity and both static and dynamic balance in women diagnosed with osteoporosis. Methods: We assessed health history, current medication and quality of life by questionnaire in 97 community-dwelling women with osteoporosis. Static balance was measured by computerized dynamic posturography (Equitest), dynamic balance by timed figure-eight run, and knee extension strength by dynamometry. Results: The 97 participants (mean (SD) age 69 (3.2) years) had a mean lumbar spine BMD of T = –3.3 (0.7) and total hip BMD of –2.9 (0.4). In stepwise linear regression, the significant determinants of static balance that explained 18% of total variance were knee extension strength (10%, p < 0.001), age (5%, p < 0.01) and tobacco use (3%, p < 0.05). The significant predictors of dynamic balance were knee extension strength (26%, p < 0.001), medications (6%, p < 0.05), age (4%, p < 0.05), height (4%, p < 0.001), as well as years of estrogen use (2%), tobacco use (2%) and weight (2%) (all p < 0.05). Knee extension strength was also associated with quality of life (r2 = 0.12, p < 0.001). Based on these models, a 1 kg/cm (∼3%) increase in mean knee extension strength was associated with 1.2, 2.4 and 3.4% greater static balance, dynamic balance and quality of life, respectively. Conclusions: Knee extension strength is a significant determinant of performance on static and dynamic balance tests in 65- to 75-year-old women with osteoporosis. In this cross-sectional study, knee extension strength explained a greater proportion of the variance in balance tests than did age. Investigation into the effect of intervention to improve knee extension strength in older women with osteoporosis is warranted.

Results of a 10 week community based strength and balance training programme to reduce fall risk factors: a randomised controlled trial in 65–75 year old women with osteoporosis

Objective—To test the efficacy of a community based 10 week exercise intervention to reduce fall risk factors in women with osteoporosis. Methods—Static balance was measured by computerised dynamic posturography (Equitest), dynamic balance by timed figure of eight run, and knee extension strength by dynamometry. Subjects were randomised to exercise intervention (twice weekly Osteofit classes for 10 weeks) or control groups. Results—The outcome in 79 participants (39 exercise, 40 control) who were available for measurement 10 weeks after baseline measurement is reported. After confounding factors had been controlled for, the exercise group did not make significant gains compared with their control counterparts, although there were consistent trends toward greater improvement in all three primary outcome measures. Relative to the change in control subjects, the exercise group improved by 2.3% in static balance, 1.9% in dynamic balance, and 13.9% in knee extension strength. Conclusions—A 10 week community based physical activity intervention did not significantly reduce fall risk factors in women with osteoporosis. However, trends toward improvement in key independent risk factors for falling suggest that a study with greater power may show that these variables can be improved to a level that reaches statistical significance.

The Influence of Back Pain on Balance and Functional Mobility in 65- to 75-Year-Old Women with Osteoporosis

Abstract: To determine whether the presence of back pain and its related disabilities are determinants of balance and functional mobility in a group of women with osteoporosis, we carried out a cross-sectional analysis of 93 community-dwelling women with osteoporosis between the ages of 65 and 75 years old. We assessed health history, anthropometrics, self-report of current physical activity level and self-report of back pain (intensity and pain-related disabilities). Balance was measured by computerized dynamic posturography and functional mobility was assessed by timed figure-of-eight test. The prevalence of back pain was high (75%) in this cohort of older women with osteoporosis. Age was the major determinant of both balance and functional mobility and accounted for 9% and 14% of the variance, respectively. After accounting for age, back pain explained an additional 9% of the variance in balance and 13% of the variance in functional mobility. The high prevalence of back pain demonstrates the importance of pain management in the treatment of osteoporosis. Furthermore, the finding of self-reported back pain as a determinant of both balance and functional mobility suggests that this measure may deserve attention when screening women with osteoporosis for fracture risk. Prospective studies are needed to determine whether pain management will improve balance and functional mobility.

Reply to: “Response to: Migraine and Vertigo: A Marriage of Convenience?”

The authors of the original article “Migraine and vertigo: a marriage of convenience?” wish to thank von Brevern and colleagues for highlighting this contentious topic. In reply to their response there are a number of pertinent points that are worthy of clarification. On the whole it would be inappropriate to repeat the key points outlined in our original article but our colleagues’ response has provided us with a further opportunity to support our case. Criteria for the diagnosis of Ménière’s disease were first developed by the American Academy of Otolaryngologists and Head and Neck Surgeons in 1972 to clarify Ménière’s disease. This was necessary because to all intents and purposes for much of the medical community, even the otolaryngological community, vertigo, and Ménière’s disease were regarded as synonymous. Success of this initiative by the American Academy of Otolaryngologists and Head and Neck Surgeons was shown by the necessary revision of these criteria to more exactly define the disorder in 1995. The International Headache Society undertook a similar venture with respect to characterizing migraine as at that time, to the medical community, all headaches were often inappropriately defined either as migraine or tension headache. The success of these classifications allowed accurate comparison of diseases and treatments between centers and across continents. In the world of dizziness there is a schism between Europe and North America. In North America, vertigo means spinning. If there is no spinning there is no vertigo. In Europe, vertigo includes spinning but can mean a sensation of movement of self or surroundings, which is not spinning, so-called nonvertiginous vertigo. This discrepancy has been addressed by the recent Barany First Iteration of 2007, which will hopefully unify dizziness and vertigo descriptions throughout the world. At the same time, the Barany Society included dizziness associated with migraine as a recognized disorder. A difficulty with respect to this arises as the International Headache Society classification of migraine with vertigo and dizziness is limited, reducing the ability of physicians, neurologists, and otologists in addressing the dizziness or vertigo in migraine and the even more ubiquitous migraine without headache (to some an oxymoron) satisfactorily.The International Headache Society classification of headache is very helpful as a first step as is the new First Iteration of Dizziness. Specifically, this First Iteration by the Barany Society draws attention to the well-established fact that the cause of much dizziness is unknown and offers support for some of it being due to migraine. The authors in their response to our article make a good case for more than a fortuitous association of migraine, Ménière’s disease and recurrent dizziness of unknown cause (nonspecific dizziness). These figures largely quantify their own work. Clearly, although they show an association, they do not offer overwhelming proof that most vertigo of unknown cause is due to migraine. In fact, they show that although there is a probable association, it may be small. When Fleming described penicillin he did not need a double-blind crossover trial (indeed, they did not exist) to show that it worked. The figures given by the authors of the response support their contention that this form of trial is essential as although their figures show that dizziness and migraine occur with greater than random occurrence, it is not by much. Migraine episodes are known to be triggered by many things, including foods, by relaxation after stress and in women in the premenstrual phase. It is quite likely that vestibular vertigo or vestibular dizziness is a trigger for migrainous disease and indeed this has been purported to experimentally. This may also explain the higher instance of migraine in Ménière’s disease patients.

Defining clinical-posturographic and intra-posturographic discordances : What do these two concepts mean?

The European Society for Clinical Evaluation of Balance Disorders - ESCEBD - Executive Committee meets yearly to identify and address clinical equilibrium problems that are not yet well understood. This particular discussion addressed discordances (defined as lack of agreement) in clinical assessment. Sometimes there is disagreement between a clinical assessment and measured abnormality (ies); sometimes the results within the assessment do not agree. This is sometimes thought of as malingering or an attempt to exaggerate what is wrong, but this is not always the case. The Committee discussed the clinical significance of unexpected findings in a patients assessment. For example intraposturographic discordances sometimes exhibit findings (eg performance on more difficult trials may sometimes be better than on simpler trials). This can be suggestive of malingering, but in some situations can be a legitimate finding. The extreme malingerer and the genuine patient are at opposite ends of a spectrum but there are many variations along this spectrum and clinicians need to be cautious, as a posturography assessment may or may not be diagnostically helpful. Sometimes there is poor correlation between symptom severity and test results. Interpretation of posturography performance can at times be difficult and a patients results must be correlated with clinical findings without stereotyping the patient. It is only in this situation that assessment in a diagnostic setting can be carried out in an accurate and unbiased manner.

Discussion about visual dependence in balance control: European society for clinical evaluation of balance disorders

The executive committee of the European Society for the clinical evaluation of balance disorders meets annually to address equilibrium problems that are not well understood. This is a review paper on discussions in the latest meeting we held.nnnMATERIALS AND METHODSnSeeing patients with vestibular disorders who end up depending on visual information as part of their compensation process is a common clinical occurrence. However, this visual dependence can generate symptoms, which include nausea, sensations of imbalance, and anxiety. It is unclear how this develops, as symptoms can be widely variable from patient to patient. There are several triggering factors to this symptom set, and quantifying it in a given patient is extremely difficult Results: The committee agreed that the presence of this symptom set can be suggestive of vestibular pathology, but the pathology does not have to be present. As a result, there is no correlation between symptom severity and test results.nnnCONCLUSIONnVisual dependence can often be present in a patient, although little, if any, measurable pathology is present. It is important to emphasize that although we cannot accurately measure this with either standardized testing or pertinent questionnaires, hypersensitive patients have a genuine disease and their symptoms are not of psychiatric origin.