Biomechanics of leaning forward against a support with an extreme standing reach.

Back discomfort, lower extremity loading and unbalanced positions may inhibit workers from standing for industrial stationary work. Two forward-leaning supports were compared to unsupported standing during an extreme reach with 30° trunk flexion under varied light load conditions in the outstretched hands. A total of 11 males from the university participated (mean age 30 years [SD =  5]).

Biomechanical measurements of surgical drilling force and torque in human versus artificial femurs.

Few experimental studies have examined surgical drilling in human bone, and no studies have inquired into this aspect for a popular commercially-available artificial bone used in biomechanical studies. Sixteen fresh-frozen human femurs and five artificial femurs were obtained. Cortical specimens were mounted into a clamping system equipped with a thrust force and torque transducer.

Force and torque modelling of drilling simulation for orthopaedic surgery.

The advent of haptic simulation systems for orthopaedic surgery procedures has provided surgeons with an excellent tool for training and preoperative planning purposes. This is especially true for procedures involving the drilling of bone, which require a great amount of adroitness and experience due to difficulties arising from vibration and drill bit breakage. One of the potential difficulties with the drilling of bone is the lack of consistent material evacuation from the drill's flutes as the material tends to clog.

Comparison of three strategies of trunk support during asymmetric two-handed reach in standing.

No trunk support (NTS) was compared to a lower trunk support (LTS) of leaning against a worktable and a dynamic upper trunk support (UTS) using postural kinematics, trunk extensor muscle activity and subjective rating of both comfort and effort. Ten females completed 3 repetitions where they lifted 0 and 5 kg load from a symmetrical position at hip-height to a 45° asymmetric position at: i) hip-height and ii) shoulder-height. Human motion capture showed trunk flexion decreased by 12° ± 10 with trunk support with hip-height reach.

Comparison of two heights for forward-placed trunk support with standing work.

Two forward-placed supports with different heights are investigated using human motion capture and EMG. Ten male participants stood in 10 degrees increments of trunk flexion between 0 and 40 degrees for three conditions; leaning on a desk adjusted to the height of the pelvis, leaning on a prototype support at the height of the sternum and with no external support. Low back and hip extensor muscle activity was reduced by an average 60% with leaning against the prototype compared to the no-support condition whereas leaning on a desk produced no significant change in muscle activity.