The purpose of this study was to investigate the influence of body function, activities and pain on the level of activity in adults with Kashin Beck Disease (KBD). Seventy-five KBD patients with a mean age of 54.8 years (SD 11.3) participated. Anthropometrics, range of joint motion (ROM) and muscle strength were measured as well as the time-up-and-go test and functional tests for the lower and upper extremities. Activity was assessed with the participation scale and the WHO DAS II. In the shoulder, elbow, hip and knee joints, a severe decrease in ROM and bilateral pain was noted. A decrease in muscle strength was observed in almost all muscles. The timed-up-and-go test scores decreased. No or mild restriction in activity was found in 35%, and 33% experienced a moderate restriction whereas 32% had severe to extreme restriction. Activities in the lower extremities were mildly to moderately correlated to ROM and muscle strength, whereas in the upper extremities activities were correlated to range of joint motion. Activity was significantly associated with ROM after correction for muscle strength, gender and age. Participation was borderline significantly associated with ROM after correction for muscle strength, gender, age and the activity time-up-and-go. In KBD adults, a severe decrease in activity is primarily caused by decrease in ROM. These findings have strong influence on rehabilitation and surgical intervention.
PURPOSE: The patients diagnosed with Ehlers-Danlos Syndrome Hypermobility Type (EDS-HT) are characterized by pain, proprioceptive inacuity, muscle weakness, potentially leading to activity limitations. In EDS-HT, a direct relationship between muscle strength, proprioception and activity limitations has never been studied. The objective of the study was to establish the association between muscle strength and activity limitations and the impact of proprioception on this association in EDS-HT patients.METHODS: Twenty-four EDS-HT patients were compared with 24 controls. Activity limitations were quantified by Health Assessment Questionnaire (HAQ), Six-Minute Walk test (6MWT) and 30-s chair-rise test (30CRT). Muscle strength was quantified by handheld dynamometry. Proprioception was quantified by movement detection paradigm. In analyses, the association between muscle strength and activity limitations was controlled for proprioception and confounders.RESULTS: Muscle strength was associated with 30CRT (r = 0.67, p = <0.001), 6MWT (r = 0.58, p = <0.001) and HAQ (r = 0.63, p= <0.001). Proprioception was associated with 30CRT (r = 0.55, p < 0.001), 6MWT (r = 0.40, p = <0.05) and HAQ (r = 0.46, p < 0.05). Muscle strength was found to be associated with activity limitations, however, proprioceptive inacuity confounded this association.CONCLUSIONS: Muscle strength is associated with activity limitations in EDS-HT patients. Joint proprioception is of influence on this association and should be considered in the development of new treatment strategies for patients with EDS-HT. Implications for rehabilitation Reducing activity limitations by enhancing muscle strength is frequently applied in the treatment of EDS-HT patients. Although evidence regarding treatment efficacy is scarce, the current paper confirms the rationality that muscle strength is an important factor in the occurrence of activity limitations in EDS-HT patients. Although muscle strength is the most dominant factor that is associated with activity limitations, this association is confounded by proprioception. In contrast to common belief proprioception was not directly associated with activity limitations but confounded this association. Controlling muscle strength on the bases of proprioceptive input may be more important for reducing activity limitations than just enhancing sheer muscle strength.
BACKGROUND: Muscle force is important for daily life and sports and can be measured with a handheld dynamometer. Reference values are employed to quantify a subject's muscle force. It is not unambiguous whether reference values can be generalized to other populations. Objectives in this study were; first to confirm the reliability of the utilization of hand-held dynamometers for isometric strength measurement; second to determine reference values for a population of Dutch workers; third to compare these values with those of a USA population.METHODS: 462 Healthy working subjects (259 male, 203 female) were included in this study. Their age ranged from 20 to 60 years with a mean (sd) of 41 (11) years. Muscle force values from elbow flexion and extension, knee flexion and extension, and shoulder abduction were measured with the break method using a MicroFet 2 hand-held dynamometer. Reliability was analyzed by calculating ICC's and limits of agreement. Muscle force expressed in Newton, means, and confidence intervals were determined for males and females in age groups ranging from twenty to sixty years old. Regression equations and explained variances were calculated from weight, height, age, and gender. The mean values and 95% CI were compared to the results from other studies.RESULTS: Reliability was good; the ICC ranged between 0.83 to 0.94. The explained variance ranged from 0.25 to 0.51. Comparison of data for the Dutch population mean muscle force values with those from the USA revealed important differences between muscle force reference values for the American and Dutch populations.CONCLUSIONS: Muscle force measurements demonstrate a sound reliability. Reference values and regressions equations are made available for the Dutch population. Comparison with other studies indicates that reference values differ between countries.
