Jane (2012) The influence of barefoot and barefoot inspired footwear on the kinetics and kinematics of running in comparison to conventional running shoes. Footwear Science, 5 (1).

No abstract

Front load carriage is a common occupational task in some industries (e.g. agriculture, construction), but, as compared to lifting tasks, relatively little research has been conducted on the biomechanical loading during these activities. The focus of this study was to explore the low back biomechanics during these activities and, specifically, to examine the effects of load height and walking speed on trunk muscle activity and trunk posture. Eleven male participants participated in two separate front load-carriage experiments. The first experiment called for carrying a barbell (with weight corresponding to 20% of elbow flexion strength) at three heights (knuckle height, elbow height and shoulder height) at a constant horizontal distance from the spine. The second experiment called for participants to carry a bucket of potatoes weighing 14 kg at the same three heights, but with no further restrictions in technique. In both experiments, the participants performed this task while either standing still or walking at a self-selected speed. As they performed these tasks, the activity levels of the right-side muscle of the rectus abdominis, external oblique, biceps brachii, anterior deltoid and three levels (T9, T12 and L3) of the erector spinae were sampled. Mid-sagittal plane trunk posture was also quantified using three magnetic field-based motion sensors at T9, T12 and L3. The results showed a significant effect of both walking speed and load height on trunk posture and trunk muscle activity levels in both the barbell and bucket experiments. In the barbell experiment, the walking trials generated 43% more trunk muscle activity than the standing trials. Trials at shoulder height produced 11% more muscle activity than trials at elbow height in the T9 erector spinae muscles and 71% more muscle activity in the anterior deltoid. In the bucket experiment, trunk muscle activity responded in a similar fashion, but the key result here was the quantification of the natural hyperextension posture of the spine used to balance the bucket of potatoes. These results provide insight into muscle activation patterns in dynamic settings, especially (load) carrying biomechanics, and have implications in industrial settings that require workers to carry loads in front of their bodies.

No abstract

We compared the Bereitschaftspotential preceding a simple foot movement while sitting and a stepping movement while standing in a group of normal subjects and seven patients with mild to moderate Parkinson's disease (PD) while off medication. None had major difficulties stepping to initiate gait. Electromyographic signals from tibialis anterior triggered the averaging of electroencephalographic signals from the scalp. Bereitschaftspotential preceding a standing stepping movement were larger than those before a foot movement while sitting in normal subjects, but no difference was observed in patients with PD. The absence of an increase in the Bereitschaftspotential when stepping in PD may reflect an impairment of the preparation and assembly of the complex sequences of movement necessary to initiate walking, even in the early stages of the illness.