A systematic review of the effect of ageing and falls history on minimum foot clearance characteristics during level walking.

Minimum foot clearance (MFC) is the minimum vertical distance between the lowest point of the foot of the swing leg and the walking surface during the swing phase of the gait cycle. MFC is a gait variable that is linked to the mechanism of a trip because reduced MFC for a given step during walking increases the susceptibility to tripping on an unseen obstacle or due to undetected changes in surface height. Given that tripping is a common cause of falls in older persons, this review was undertaken to determine whether ageing and/or history of falls in older adults influences MFC characteristics during level walking. Studies that assessed MFC characteristics including measures of central tendency (mean and/or median), variability (linear and non-linear measures) and shape (skewness, kurtosis) of the MFC distribution were included in the review. The final yield from a search of seven electronic research databases was 12 unique articles that met all the inclusion criteria. Ageing does not appear to alter measures of central tendency or shape of the MFC distribution. However greater MFC variability was observed in older compared to younger adults and older fallers compared to older non-fallers in the majority of studies. Greater MFC variability may contribute to increased risk of trips and associated falls in older compared to young adults and older fallers compared to older non-fallers.

Tibio-femoral cartilage defects 3-5 years following arthroscopic partial medial meniscectomy.

OBJECTIVE: Arthroscopic partial medial meniscectomy (APMM) is a common procedure to treat a medial meniscal tear. Individuals who undergo APMM have a heightened risk of developing tibio-femoral osteoarthritis (OA). Cartilage defects scored from magnetic resonance imaging (MRI) scans predict cartilage loss over time. It is not known whether cartilage defects in the early years following APMM are more common or of greater severity than in age-matched controls. This study compared the prevalence and severity of tibio-femoral cartilage defects in patients 3-5 years post-APMM with that of age-matched controls. METHODS: Twenty-five individuals who had undergone APMM in the previous 46.9+/-5.0 months and 24 age-matched controls participated in this study. Sagittal plane knee MRI scans were acquired from the operated knees of patients and from randomly assigned knees of the controls and graded (0-4) for tibio-femoral cartilage defects. Defect prevalence (score of >or=2 for any compartment) and severity of the cartilage from both tibio-femoral compartments were compared between the groups. RESULTS: The APMM group had greater prevalence (77 vs 42%, P=0.012) and severity (4.1+/-1.9 vs 2.8+/-1.1, P=0.005) of tibio-femoral cartilage defects than controls. Age was positively associated with tibio-femoral cartilage defect severity for APMM, r=0.523, P=0.007, but not for controls, r=0.045, P=0.834. CONCLUSION: Tibio-femoral joint cartilage defects are more prevalent and of greater severity in individuals who had undergone APMM approximately 44 months earlier than in age-matched controls.

Supplementation of a home-based exercise programme with a class-based programme for people with osteoarthritis of the knees: a randomised controlled trial and health economic analysis.

OBJECTIVES: To establish the relative effectiveness and cost of providing a home-based exercise programme versus home-based exercise supplemented with an 8-week class-based exercise programme. DESIGN: The trial was a pragmatic, single-blind randomised clinical trial accompanied by a full economic evaluation. SETTING: Patients were randomly allocated to either home-based exercise or home exercise supplemented with class exercise programmes. PARTICIPANTS: A total of 214 patients, meeting the American College of Rheumatology's classification of knee osteoarthritis, were selected from referrals from the primary and secondary care settings. INTERVENTIONS: Both groups were given a home exercise programme aimed at increasing lower limb strength, and endurance, and improving balance. The supplemented group also attended 8 weeks of twice-weekly knee classes run by a physiotherapist. Classes represented typical knee class provision in the UK. MAIN OUTCOME MEASURES: Assessments of locomotor function, using a timed score of three locomotor activities, walking pain and self-reported disability with the Western Ontario and McMaster's Universities osteoarthritis index (WOMAC) were made. General health, lower limb strength, range of movement and compliance with exercise were also measured. Patients were assessed before and after treatment, and also at 6- and 12-month follow-ups. The economic evaluation looked at health service resource use and assessed cost-effectiveness by relating differential costs to differences in quality-adjusted life-years (QALYs) based on patients' responses to the EuroQol-5 Dimensions. Data were obtained at baseline, 1 month, 6 months and 12 months through face-to-face interviews and, where appropriate, examination of hospital medical records. RESULTS: Patients from the supplemented group demonstrated significantly greater improvement in locomotor function and decrease in pain while walking at all follow-ups. The supplemented group also demonstrated smaller but significant improvements in balance, strength, WOMAC score, and the physical function and pain dimensions of the Short Form-36. However, not all of these improvements were maintained over the 12-month follow-up period. There was no evidence that compliance with the home exercise programme was different or that total costs or mean QALY gains were significantly different between the groups. However, costs were slightly lower and QALY gains slightly higher in the group with the supplementary class-based programme. The economic evaluation suggests that supplemented programmes are likely to be considered cost-effective, although there is uncertainty around this estimate, with approximately 30--35% probability that the intervention would not be cost-effective. CONCLUSIONS: The supplementation of a home-based exercise programme with a class-based exercise programme led to superior improvement in the supplemented group. These differential improvements were still evident at review 12 months after treatment had ceased. The additional cost of the supplemented group was offset by reductions in resource use elsewhere in the system. Compliance with the home exercise programme did not differ between the groups. Based on this evidence, the supplementation of a home-based exercise programme with an 8-week class-based exercise programme can be confidently expected to produce small improvements in locomotor function and clinically important reductions in pain. It is recommended that future research investigates methods of increasing compliance with home exercise programmes and evaluates the impact of these interventions in the primary care setting, where most patients with knee osteoarthritis are managed.

Supplementing a home exercise programme with a class-based exercise programme is more effective than home exercise alone in the treatment of knee osteoarthritis.

OBJECTIVE: The study aimed to compare the relative effectiveness of providing a home-based exercise programme versus home-based exercise supplemented with an 8-week class-based exercise programme in reducing pain and improving function in patients with knee osteoarthritis. METHODS: Patients (n = 214) with radiologically confirmed knee osteoarthritis were selected. Patients were randomly allocated to either home or home supplemented with class-based exercise programmes. Both groups were given a home exercise programme whilst the supplemented group also attended for 8 weeks of twice weekly knee classes. Assessments of locomotor function, walking pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were made. Assessments were made pre- and post-treatment and also at 6- and 12-month follow-ups. Statistical analysis involved the use of a longitudinal linear model ANCOVA with baseline values entered as a covariate. RESULTS: Patients from the class-based group demonstrated significantly greater improvement in locomotor function (-3.7 seconds; 95% C.I. -4.9 to -2.5) and decrease in walking pain (-15 mm; 95% C.I. -20 to -11) than the home-based group, at 12-months follow-up. CONCLUSIONS: The supplementation of a home based exercise programme with a class-based exercise programme led to clinically significant superior improvement. These improvements were still evident at 12-month review. This is the first trial to evaluate this common physiotherapeutic practice, and based on this evidence, supplementation of home exercises with a class-based exercise programme can be recommended to patients, clinicians and service providers.

Quadriceps muscles vastus medialis obliques, rectus femoris and vastus lateralis compared via electromyogram bicoherence analysis.

Bicoherence analysis is applied to electromyogram (EMG) data for vastus medialis obliques (VM), rectus femoris (RF) and vastus lateralis (VL) quadriceps muscles of 18 adult male subjects for isometric knee extension exercise. Mean average bicoherence for VM, RF and VL is 30.9 +/- 5.8, 26.0 +/- 1.2 and 25.4 +/- 1.4% respectively and repeated measures ANOVA differentiates the muscles on the basis of average bicoherence (F = 16.2 (1, 17), p = 0.0009, VM cf. VL and F = 15.4 (1, 17), p = 0.0011, VM cf. RF). Prominent regions representative of strong second-order phase coupling between constituent EMG frequencies are identified within VM and RF bicoherence spectra. No such prominent regions are identified for VL which is thought to be less activated than VM during the specified task. Hence, the degree of second-order phase coupling may increase as the level of muscle activation increases. The subject group consists of young (24.0 +/- 0.9 years) and elderly (68.9 +/- 0.9 years) subgroups that cannot be differentiated by standard indices (median and spectral edge frequency) to within p < 0.05 using the Mann-Whitney test. Average bicoherence differentiates the subgroups for RF (T = 9 (8,10), p < 0.005) but not for VM or VL. The application of a bicoherence threshold that takes harmonic amplitude into account graphically differentiates the subgroups for all muscle types. The findings suggest that nonlinear processes play a role within the EMG generation process and support a mechanomyogram bicoherence analysis study that shows nonlinear processes occur within active muscle fibre twitch summation patterns. A potential exists for bicoherence analysis to complement standard EMG frequency analysis techniques.

Bicoherence analysis of quadriceps electromyogram during isometric knee extension.

Bicoherence analysis is applied to electromyogram (EMG) data for the vastus lateralis quadriceps muscle of 18 adult male subjects for isometric knee extension exercise. Bicoherence spectra display ridge-like features that are indicative of deterministic chaotic behaviour and similar to those reported for normal electrocardiogram and electroencephalogram bicoherence spectra. No other obvious features are visually identified within bicoherence spectra in response to the stimulus of isometric tension. Histograms that show the occurrence of constituent EMG frequencies associated with the strongest bicoherence display subtle fluctuations. Validation tests that include the analysis of white noise data show these fluctuations to most likely be a consequence of the normal time evolution of a deterministic chaotic process. The finding suggests that second-order phase coupling is not pronounced between any particular bands of constituent EMG frequencies for the vastus lateralis EMG generation process during the specified isometric task. Previous studies into bicoherence analysis of EMG data are not apparent in the literature for comparison. Since nonlinear processes are known, through mechanomyogram bicoherence analysis, to be significant within active muscle fibre twitch summation patterns, the finding does not exclude the potential for bicoherence analysis to complement standard EMG frequency analysis techniques in the area of sports rehabilitation and medicine. Further investigation is required to establish whether this potential exists. An introduction to bicoherence analysis theory is also presented.

Strength-duration testing of the external anal sphincter in females with anorectal dysfunction.

PURPOSE: The strength-duration test has been suggested as a means of assessing external anal sphincter function. This study was designed to investigate this claim by comparing the strength-duration test with established measures of external anal sphincter function. METHODS: Forty-nine females undergoing diagnostic anorectal testing (manometry, rectal sensation, electromyogram, pudendal nerve terminal motor latency, and endoanal ultrasound) also had the strength-duration test performed (which was repeated for each patient after a short rest period). RESULTS: The strength-duration test was repeatable. Statistically significant correlations were found between this test at pulse durations of 3 ms, 1 ms, and 0.3 ms with electromyographic activity of the external anal sphincter and with pressure in the anal canal during voluntary contraction. Significant correlations were found for durations of 100 ms, 30 ms, 10 ms, and 3 ms with the pudendal nerve terminal motor latency on the right and for the 3 ms and 0.3 ms durations with latency on the left. There were no correlations between the strength-duration test and resting pressure in the anal canal. CONCLUSION: The strength-duration test significantly correlates with the established measures of external anal sphincter function and its innervation. Therefore, this simple test appears to provide a simple measure of external anal sphincter denervation.

Swing phase mechanics of healthy young and elderly men.

This study examined the effect of ageing on the swing phase mechanics of young and elderly gait. Sagittal plane marker trajectories and force plate data were collected while 10 young (24.9+/-0.9 years) and eight elderly (68.9+/-0.4 years) subjects walked at their preferred walking speeds. Comparison between young and elderly gait was made for a range of spatial-temporal, kinematic and kinetic variables with emphasis given to identifying possible differences at toe-off, minimum metatarsal-phalangeal joint clearance and heel contact. In order to control for the confounding effect of gait velocity on the dependent variables, a multivariate analysis of covariance was used to identify differences between the young and elderly subjects due to age. In contrast to studies that have reported lower preferred walking speeds in the elderly compared to the young [J.O. Judge, R.B. Davis III, S. Ounpuu, Step length reductions in advanced age: the role of ankle and hip kinetics, Journal of Gerontology: Medical Sciences 51 (1996) M303-312; D.C. Kerrigan, M.K. Todd, U. Della Croce, L.A. Lipsitz, J.J. Collins, Biomechanical gait alterations independent of speed in the healthy elderly: evidence for specific limiting impairments, Archives of Physical and Medical Rehabilitation 79 (1998) 317-322], no differences in walking speed nor in the spatial-temporal variables that determine walking speed were detected. The elderly were however, found to have a greater hip extension moment at the time of minimum metatarsal-phalangeal joint clearance, and a significantly higher anterior-posterior velocity heel contact velocity that was linked to a significantly higher shank and foot angular velocity at heel contact. Since many gait variables are highly correlated with walking speed [C. Kirtley, M.W. Whittle, R.J. Jefferson, Influence of walking speed on gait parameters, Journal of Biomechanical Engineering 7 (1985) 282-288; D.A. Winter, Biomechanical motor patterns in normal walking, Journal of Motor Behaviour 15 (1983) 302-330], differences between young and elderly gait found in the present study may therefore be attributed to ageing, rather than a secondary effect of differences in gait velocity.

Stromal cells in cerebellar haemangioblastomas: an immunocytochemical study.

The nature of the stromal cells in formalin-fixed paraffin-embedded material from 23 cerebellar haemangioblastomas was investigated using antisera to intermediate filaments (glial fibrillary acidic protein, vimentin and desmin), histiocytic markers (alpha 1-antitrypsin, alpha 1-antichymotrypsin and lysozyme), glycolytic enzymes (alpha and gamma enolase and aldolase C4) and the endothelial markers, factor VIII related antigen and Ulex europaeus I lectin. Most stromal cells stained positively for vimentin and the glycolytic enzymes. Occasional process-bearing cells within the stroma stained strongly for glial fibrillary acidic protein, alpha 1-antitrypsin and alpha 1-antichymotrypsin. No stromal cell staining for desmin, lysozyme or the endothelial markers was observed, although the latter stained the vascular endothelium within all neoplasms. The findings do not support previous suggestions of an endothelial or histiocytic origin for the stromal cells. They appear to be a heterogeneous population including entrapped reactive astrocytes and locally-derived non-angiogenic cells of neuroectodermal (pial) origin.

On the nature of clear cell acanthomas.

Five clear cell acanthomas were studied using a panel of immunohistological markers. The results were compared with those from basal cell papillomas, with and without clear cell change, and with lesions of psoriasis and lichen planus. The results do not support the contention that these lesions are variants of basal cell papillomas nor that they are true neoplasms.

Giant vascular eccrine spiradenomas: a report of two cases with histology, immunohistology and electron microscopy.

Two examples of a variant of benign spiradenoma are reported, both characterized by their large size and high degree of vascularity. The results of studies using light microscopy, transmission electron microscopy and immunohistology are described. The relationship of this unusual variant to other spiradenomas and their eccrine sweat gland origin is discussed. The possible misdiagnosis of this rare type of spiradenoma is emphasized.

Adenomatoid tumours: an immunohistochemical and ultrastructural appraisal of their histogenesis.

The histogenesis of adenomatoid tumour has continued to provoke debate since Golden and Ash suggested the term in 1945 for a characteristic benign neoplasm typically found in the uterus, fallopian tube or epididymis. Endothelial, epithelial, mesonephric, müllerian and mesothelial histogenesis have been suggested. The balance of evidence suggests mesothelial derivation, but two recent studies point to endothelial origin for at least some of these tumours. Twenty-two histologically typical adenomatoid tumours were studied by electron microscopy, mucin histochemistry and immunohistochemistry. Ultrastructurally, all cases showed vacuolated cells bearing long bushy microvilli and the features were not those of endothelial cells. Glandular spaces contained acid mucopolysaccharide consistent with hyaluronic acid. Immunohistochemical double labelling techniques showed the cells lining such spaces to contain cytokeratin in the absence of factor VIII related antigen and receptors for Ulex europaeus I lectin which were expressed in the endothelium of tumour blood vessels. The evidence points to mesothelial histogenesis in all cases examined.

Comparison of Ulex europaeus I lectin binding and factor VIII-related antigen as markers of vascular endothelium in follicular carcinoma of the thyroid.

Factor VIII-related antigen (F VIII-RAg), a well established marker for endothelial cells, and the lectin Ulex europaeus agglutinin I (UEA-1), a newly described marker, were used in immunoperoxidase techniques to demonstrate endothelial cells in 30 follicular neoplasms of the thyroid and so to assist in detection of vascular invasion. Both endothelial cell markers made visible a greater number of instances of vascular invasion than were detected on routine elastic stains, but UEA-1 lectin gave more reliable staining of endothelium lining large capsular veins and of blood vessels within the tumour than did F VIII-RAg. In vessels completely occluded by tumour, examples of endothelial staining by UEA-1 in the absence of F VIII-RAg staining were found, but some such vessels appeared to lack surviving endothelial cells and in these no staining occurred. It is concluded that UEA-1 lectin is a more reliable endothelial marker in this setting than F VIII-RAg and may assist the demonstration of vascular invasion in these tumours.

Monoclonal antibodies to blood group isoantigens: an alternative marker to factor VIII related antigen for benign and malignant vascular endothelial cells.

Monoclonal antibodies to A, B and H blood group isoantigens (BGI) were used in an indirect immunoperoxidase technique to compare the distribution of BGI expression as a marker of vascular endothelial cells with that of coagulation factor VIII related antigen (F VIII-RAg), a well established marker for vascular endothelium. Formalin-fixed and paraffin-embedded material from 70 specimens representing a wide range of reactive and benign or malignant neoplastic states of the vascular endothelium was used to provide adjacent serial tissue sections to compare directly the tissue expression of BGI and of F VIII-RAg. In reactive and benign neoplastic conditions of the vascular endothelium, cell membrane expression of the BGI appropriate to the patient's blood group was readily detected. In the more cellular and proliferative areas of some haemangiomas, pyogenic granulomas and cases of angiolymphoid hyperplasia with eosinophilia, BGI proved a superior marker of the endothelial cells compared with F VIII-RAg. The malignant endothelial cells of 27 specimens of angiosarcoma showed deletion of BGI expression in 24 and of F VIII-RAg in 19. Expression of neither antigen showed any significant correlation with the degree of tumour differentiation. Some cases of lymphangioma, uniformly negative for F VIII-RAg staining, showed strong expression of BGI. The possible use of BGI expression as a marker of vascular endothelium is discussed in the light of the known tissue expression of F VIII-RAg.