Inter-individual similarities and variations in muscle forces acting on the ankle joint during gait

Muscle forces acting over the ankle joint play an important role in the forward progression of the body during gait. Yet despite the importance of ankle muscle forces, direct in-vivo measurements are neither possible nor practical. This makes musculoskeletal simulation useful as an indirect technique to quantify the muscle forces at work during locomotion. The purpose of this study was to: 1) identify the maximum peaks of individual ankle muscle forces during gait; 2) investigate the order over which the muscles are sorted based on their maximum peak force. Three-dimensional kinematics and ground reaction forces were measured during the gait of 10 healthy subjects, and the data so obtained were input into the musculoskeletal model distributed with the OpenSim software. In all 10 individuals we observed that the soleus muscle generated the greatest strength both in dynamic (1856.1N) and isometric (3549N) conditions, followed by the gastrocnemius in dynamic conditions (1232.5N). For all other muscles, however, the sequence looks different across subjects, so the k-means clustering method was used to obtain one main order over which the muscles’ peak-forces are sorted. The results indicate a common theme, with some variations in the maximum peaks of ankle muscle force across subjects

COMPARISON OF THREE MOTION ANALYSIS PROGRAMS BASED ON THE SHOT PUT PERFORMANCE

The aim of the study was to compare the results obtained using the three programs: Vicon, OpenSim and AnyBody. The feasibility of the application and of the selection of one of the programs for further analysis of the sport technique was checked. In the experiment herewith, the torque and power as function of time in the joints of the lower limb during the last phase of shot put was computed. Examinations of the kinematic and kinetic parameters of analyzed movement were carried out using Vicon system and Kistler force plates. Three top level national competitors took part in the study. The differences between the torques and power were checked with a modified RMS index. The results obtained indicate that OpenSim program may be useful for further studies, and in particular in controlling and analyzing the neuromusculaskeletal system

Assessment of lower leg muscle force distribution during isometric ankle dorsi and plantar flexion in patients with diabetes: a preliminary study.

AIM The aim of this study was to evaluate the differences in ankle muscle strength using hand-held dynamometry and to assess difference in the isometric muscle force distribution between the people with diabetes and control participants. METHODS The maximal muscle strength of ankle plantarflexion, dorsiflexion, eversion, inversion, lesser toes flexors and extensors, hallux flexors, and extensors was assessed in 20 people with diabetes and 20 healthy participants using hand-held dynamometry. The maximal isometric ankle plantarflexion and dorsiflexion were imported to OpenSim software to calculate 12 individual muscle (8 plantarflexors and 4 dorsiflexors) forces acting on ankle joint. RESULTS A significant reduction in ankle strength for all measured actions and a significant decrease in muscle force for each of the 12 muscles during dorsi and plantar flexion were observed. Furthermore, the ratios of agonist to antagonist muscle force for 6 of the muscles were significantly different between the control group and the group with diabetes. CONCLUSIONS It is likely that the muscles for which the agonist/antagonist muscle force ratio was significantly different for the healthy people and the people with diabetes could be more affected by diabetes