Papers by Anastasia Protopapadaki
Background and purpose: The ability to perfonn everyday activities is essential for maintaining i... more Background and purpose: The ability to perfonn everyday activities is essential for maintaining independence in daily life. A number of studies have reported the effect of hip and knee osteoarthritis (OA) on biomechanical characteristics of the lower limb during gait. There is a dearth of studies reporting biomechanical analysis of stair climbing in OA subjects, particularly those with hip OA. Thet:efore, the pwpose ofthis study was to investigate the impact of hip and knee OA on the biomechanical characteristics ofhip, knee and ankle joints during stair climbing and gait. Methods: Three age matched groups (range 50-75 years) participated in this study: control group, hip OA group and knee OA group. The laboratory staircase consisted of 4 steps (rise height 18 cm, tread length 28.5 em). Sagittal joint angles, vertical ground reaction forces, sagittal joint moment, and EMG activity of lower limb muscles were recorded using 3D Vicon motion analysis system, Bertec force plates and Telemetry EMG. . Results: Both hip and knee OA subjects moved with significantly (p<0.05) slower speed during gait, stair ascent and stair descent which were accompanied with alterations in lower limb kinematics, kinetics and EMG activity in comparison to the controls. Hip OA subjects showed a significant (p<O.OI) lack of hip extension during gait and significantly (p<0.01) reduced hip range of motion during gait and stair ascent in comparison to the control and knee OA subjects. Hip OA subjects also showed significantly reduced hip range of motion during stair descent compared to controls. In comparison to the controls,. knee OA subjects walked, ascended and descended the stairs with significantly (p<0.01) reduced maximum knee flexion angles. In comparison to the controls significant (p<0.05) reductions were found in external hip flexion and knee extension moments during gait for hip OA group and in external ankle dorsiflexion moments during all three tasks for knee OA group. Both hip and knee OA subjects showed significantly (p<O.OI) increased EMG activity for vastus medialis obliquus during gait and stair ascent. In comparison to the controls knee OA subjects also showed significantly increased EMG activity for biceps femoris during gait (p<O.05) and stair descent (p<O.OI) and for rectUs femoris (p<0.01) and gluteus maximus (p<O.05) during stair ascent. Conclusion: The most critical findings for hip OA subjects were the reduced speed, lack of hip extension and the reduced external hip extension moments during stance phase of gah. For knee OA subjects key findings included reduced speed, maximum knee flexion angles and external ankle dorsiflexion moments during all three tasks. Indications from this study are that interventions that enhance hip extension for hip OA subjects arid knee flexion for knee OA subjects could improve functional ability in hip and knee OA populations. Furthennore, these data can be used to evaluate pre and post arthroplasty function and help in the design of prosthetic devices with consideration given to whole lower limb biomechanics.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Clinical Biomechanics, 2007
Background. Few studies have reported the biomechanical aspects of stair climbing for this ergono... more Background. Few studies have reported the biomechanical aspects of stair climbing for this ergonomically demanding task. The purpose of this ethically approved study was to identify normal functional parameters of the lower limb during stair climbing and to compare the actions of stair ascent and descent in young healthy individuals. Methods. Thirty-three young healthy subjects, (16 M, 17 F, range 18-39 years) participated in the study. The laboratory staircase consisted of four steps (rise height 18 cm, tread length 28.5 cm). Kinematic data were recorded using 3D motion analysis system. Temporal gait cycle data and ground reaction forces were recorded using a force platform. Kinetic data were standardized to body mass and height. Findings. Paired-samples t tests showed significantly greater hip and knee angles (mean difference standard deviation (SD): hip 28.10°(SD 4.08), knee 3.39°(SD 7.20)) and hip and knee moments (hip 0.25 N m/kg (SD 0.18), knee 0.17 N m/kg (SD 0.15)) during stair ascent compared to descent. Significantly greater ankle dorsiflexion angles (9.90°(SD 3.80)) and plantarflexion angles (8.78°(SD 4.80)) were found during stair descent compared to ascent. Coefficient of variation (mean (SD)) in percentage between repeated tests varied for joint angles and moments, respectively (2.35% (SD 1.83)-17.53% (SD 13.62)) and (4.65% (SD 2.99)-40.73% (SD 24.77)). Interpretation. Stair ascent was shown to be the more demanding biomechanical task when compared to stair descent for healthy young subjects. The findings from the current study provide baseline measures for pathological studies, theoretical joint modelling, and for mechanical joint simulators.
Clinical Biomechanics, 2007
Background. Few studies have reported the biomechanical aspects of stair climbing for this ergono... more Background. Few studies have reported the biomechanical aspects of stair climbing for this ergonomically demanding task. The purpose of this ethically approved study was to identify normal functional parameters of the lower limb during stair climbing and to compare the actions of stair ascent and descent in young healthy individuals.
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Papers by Anastasia Protopapadaki