Load Carriage-Related Paresthesias: Part 1: Rucksack Palsy and Digitalgia Paresthetica.

This is the first of a two-part article discussing loadcarriage- related paresthesias, including brachial plexus lesions (rucksack palsy), digitalgia paresthetica, and meralgia paresthetica. Paresthesias are sensations of numbness, burning, and/or tingling, usually experienced as a result of nerve injury, compression, traction, or irritation. Rucksack palsy is a traction or compression injury to the brachial plexus, caused by the shoulder straps of the rucksack. The patient presents with paresthesia, paralysis, cramping with pain, and muscle weakness of the upper limb. Muscle-strength losses appear to be greater in those carrying heavier loads. Hypothetical risk factors for rucksack palsy include improper load distribution, longer carriage distances, and load weight. Nerve traction, compression, and symptoms may be reduced by use of a rucksack hip belt; wider, better-padded, and proper adjustment of the shoulder straps; reduction of weight in the rucksack; a more symmetric distribution of the load; and resistance training to improve the strength and hypertrophy of the shoulder muscles. Assessment and neck joint and nerve mobilization may relieve brachial plexus tension and reduce symptoms. Another load-carriage-related disorder is digitalgia paresthetica, likely caused by compression of the sensory digital nerves in the foot during load carriage. Patients have paresthesia in the toes. Although no studies have demonstrated effective prevention measures for digitalgia paresthetica, reducing loads and march distances may help by decreasing the forces and repetitive stress on the foot and lower leg. Specialty evaluations by a physical therapist, podiatrist, or other healthcare provider are important to rule out entrapment neuropathies such as tarsal tunnel syndrome. Part 2 of this article will discuss meralgia paresthetica.