Abstract
This study presents lower limb joint load comparison from subject specific musculoskeletal model simulation (MSK-MS) and direct measurements from instrumented implants on post-operative (PO) patients. A case study was considered for MSK-MS gait analysis of a 40-year-old healthy male with 70 kg and 1.86 m height. Reflective adhesive markers were applied on skin surface of selected anatomical points at right and left lower limbs. Orthostatic and dynamic acquisition on normal gait (NG), stiff-knee gait (SKG) and slow running (SR) was performed from ground reaction forces with two force plates at 2 kHz and trajectories of skin markers with eight-camera system at 100 Hz. Subject specific MSK-MS was performed using AnyGait and morphed Twente Lower Extremity Model (TLEM), matching the size and joint morphology of the stick-figure model. Over-determinate kinematic analysiswas performed, and motion equations solved with hard and soft constraints. Representative MSK-MS gait cycles were selected at NG, SKG and SR lower limb joint vertical force components at the hip, the knee, and the ankle normalized to body weight (JFz/BW). Internal joint direct measurements of four PO patients', 61-83 years, average weight 808 N and 1.71 m height, with telemetric Hip I (4-channel), Hip II (8-channel) and knee (9-channel) instrumented implants were selected from Orthoload database with comparable gait to NG, SKG and SR. Statistical measurements presented similar mean JFz/BW at right/left hip, knee, ankle MSK-MS and asymmetric peak values with dominant NG, SKG and SR different variances (p < 0.05). Direct JFz/BW measures contrasted NG with similar hip and knee mean and variance from SKG and SR with different mean and variance. Peak JFz/BW direct measurements presented higher hip and knee values on SR and NG than SKG, with higher values at the knee than the hip on NG and SKG, and the opposite on SR. Direct JFz/BW measurements presented at the hip and the knee lower values than their corresponding MSK-MS on NG, SKG and SR.

Abstract
This paper analyses periodic gaits of multi legged locomotion systems. The joint signals are studied in the Fourier domain, namely, from the point of view of its reproducibility through low-pass actuators, The influence of several parameters is also considered and their critical values are investigated.

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Abstract
The construction industry has been the sector that reports a higher incidence of fatal accidents all over the world. Several studies have been conducted in order to address the causes of higher rates of accidents in this sector. However, the contribution of manual material handling tasks for the occurrence of falls, in the construction industry, has been neglected. This paper presents a case study through laboratory simulation of manual material handling tasks during obstacle clearance in order to address the contribution of these tasks in accident occurrence. The results showed differences in the pattern of obstacle clearance.

Abstract
The construction industry has been the sector that reports a higher incidence of fatal accidents all over the world. Several studies have been conducted in order to address the causes of higher rates of accidents in this sector. These studies point out, among other factors, the occurrence of trips and slips in obstacles and structures as major causal factors for the occurrence of falls. In spite of the enormous amount of tasks, in the construction process, involving manual material handling of loads and its negative effect on postural balance and risk perception, the contribution of these tasks for the occurrence of falls, in the construction industry, is scarce. This paper presents a laboratory simulation study of the contribution of manual material handling tasks for the occurrence of falls through the analysis of the force required to preserve postural balance during obstacle clearance. A sample of eight construction workers participated on this study, which were attached, by an harness, to a load cell in order to analyse the force exerted during the performance of each trial. The results showed an increase of the applied force when the task was performed with the handling of a load