What physical characteristic is associated with lower cervical and upper thoracic cord lesions?

Flaccidity of the legs and portions of the arms is associated with lower cervical and upper thoracic cord lesions due to the disruption of neural pathways that control muscle tone and movement. In such lesions, the communication between the brain and the muscles is impaired, leading to a lack of muscular resistance known as flaccidity. This condition results from lower motor neuron involvement, where the spinal cord injury affects the anterior horn cells, causing weakness and reduced tone in the affected areas of the body.

When there is a lesion in the lower cervical or upper thoracic region, the neural signals that would typically activate the muscles in the legs and portions of the arms are interrupted. As a result, these muscles may become hypotonic, leading to weakness and decreased voluntary movement, which is characteristic of flaccidity.