An important prerequisite to carry out daily activities is the sit-to-stand movement. However, in obese people, this movement is characterized by altered biomechanics, which might lead to daily life activity impairments. The aim of this study was to investigate whether there are differences in kinetic and kinematic variables between three different BMI categories when performing a specific sit-to-stand test. Thirty-six adult women (BMI = 17–45 kg/m2) performed the sit-to stand test five times consecutively and as quickly as possible. Analyses of variance were used to determine differences between three BMI groups (normal or overweight: BMI < 30 kg/m2; obese: 30 ≤ BMI < 35; severely obese: BMI ≥ 35). Peak and mean vertical sacrum velocity indicated a decrease in severely obese subjects. Obese and severely obese individuals did not show higher fatigue over the five consecutive movements. Peak force and rate of force development decreased in normal or overweight subjects. The ability to successfully complete the test decreased with a higher BMI, probably due to a reduced ability to rapidly generate a high force.
Stefan Schmid, Stéphane Armand, Zoltan Pataky, Alain Golay and Lara Allet
Clément Theurillat, Ilona Punt, Stéphane Armand, Alice Bonnefoy-Mazure and Lara Allet
Assessment of ankle mobility is complex and of clinical relevance after an ankle sprain. This study develops and tests a biomechanical model to assess active ankle circumduction and its reliability. The model was then applied to compare individuals’ ankle mobility between injured and noninjured ankles after a sprain episode. Twenty patients with subacute unilateral ankle sprain were assessed at 4 weeks and 10 weeks after the injury. They underwent a clinical exam and an ankle circumduction test during which the kinematics were recorded with an optoelectronic device. A biomechanical model was applied to explore ankle kinematics. Reliability of the ankle circumduction tests were good to excellent (ICC of 0.55–0.89). Comparison between noninjured and injured ankles showed a mobility deficit of the injured ankle (dorsiflexion = −27.4%, plantar flexion = −25.9%, eversion = −27.2%, and inversion = −11.6%). The model allows a graphical representation of these deficits in 4 quadrants. Active ankle circumduction movement can be reliably assessed with this model. In addition, the graphical representation allows an easy understanding of the mobility deficits which were present in all 4 quadrants in our cohort of patients with subacute ankle sprain.