Body movements in climbing a ladder.

Descriptions are given of the following movements of the body during the action of climbing a ladder: (1) displacement and rotation of the pelvic girdle and trunk and (2) rotation of the knee and hip joints. The descriptions are derived from cine records of a laboratory experiment in which thirty five male subjects climbed a ladder set at two angles: 70·4° and 75·2° with the horizontal. A comparison is made with the actions of the walking stride. The results indicate that, at the steeper ladder angle, the hands play a greater part in maintaining the balance of the body and there are greater differences between the movement patterns of tall and short subjects. Those, in turn, suggest a decreased stability of the body and increased deviation from the average pattern of movement. This may have a bearing on the kind of ladder accident in which the man slips or misses his footing.