Using crutches to maintain mobility after a lower-limb injury forces the body to adapt to a radically different method of locomotion. This shift from using the large muscles of the legs to relying on the upper body and arms confirms that maneuvering with crutches constitutes a demanding physical activity. This modified movement drastically alters the body’s energy demands compared to walking without assistance. Scientific data consistently shows that crutch use burns substantially more energy than typical walking.
How Crutch Use Impacts Calorie Expenditure
The act of moving with crutches significantly increases the metabolic load, transforming simple movement into a cardiovascular challenge. Studies confirm that the energy cost of ambulating with standard axillary crutches is approximately twice as great as walking normally. This means the body must work nearly 200% harder to cover the same distance.
This increased energy demand pushes the cardiovascular system far beyond its normal resting state. Research indicates that oxygen consumption rises by at least 141% and heart rate increases by 47% compared to unassisted walking. This level of exertion provides a temporary aerobic benefit, depending on the duration and speed of travel.
The intensity of crutch walking can be quantified using metabolic equivalents (METs). Non-weight-bearing crutch walking on level ground often requires an effort of about 4.5 METs, resulting in a mean heart rate around 117 beats per minute (bpm) for a healthy adult.
This physiological response is due to transferring the body’s weight, normally managed by the legs, to the smaller muscle groups of the upper body. The forced reliance on these upper-body muscles rapidly elevates the need for oxygen and energy. Even simple tasks like climbing stairs demand higher energy expenditure with crutches, illustrating the strenuous nature of the activity.
Specific Muscle Groups Targeted
The biomechanics of crutch walking fundamentally change which muscle groups are responsible for stability and propulsion. During the swing-through phase, the upper extremity joints absorb the body’s entire weight, transferring the load to the arms and torso. This mechanical shift places a strengthening stimulus on the muscles of the chest, back, and arms.
The triceps brachii muscle becomes the primary pushing muscle. It is responsible for the forceful extension of the elbow that lifts the body off the ground and drives it forward. The latissimus dorsi, a large muscle of the back, works alongside the triceps to depress the shoulder girdle, simulating the push needed to elevate the body.
Significant demands are placed on the shoulder stabilizers, including the deltoid muscles and the rotator cuff group. These muscles engage intensely to manage the torque and force transmitted through the shoulder joint as body weight is supported by the hands. The strength and endurance of the upper extremities are challenged to maintain control and balance.
The trunk muscles, or core, are constantly engaged to maintain stability and prevent excessive swaying during the gait’s swing phase. The abdominal and lower back muscles work isometrically to stabilize the spine and pelvis. This continuous stabilization work provides a conditioning effect distinct from the strengthening stimulus received by the arms.
Optimizing Technique for Safety and Fitness
To maximize the fitness benefits of crutch ambulation while avoiding injury, proper technique and fit are paramount. The most serious risk associated with improper use of axillary crutches is nerve damage, often referred to as crutch palsy. This injury occurs when users mistakenly rest their body weight on the axillary pads, compressing the nerves that run through the armpit.
Weight should be borne entirely by the hands and wrists, specifically through the hand grips, not the underarm pads. Correct crutch height is determined by ensuring the top of the axillary pad sits about two finger-widths (1 to 1.5 inches) below the armpit. This gap prevents harmful pressure on the nerves when the user pushes down.
The hand grip must be adjusted so the elbow is bent at approximately a 30-degree angle when standing upright. This slight bend allows the triceps and other upper-body muscles to engage effectively for propulsion and support. Users should focus on maintaining a stable trunk and upright posture, which better engages the core muscles.
Managing fatigue is also a safety measure, as exhaustion can lead to poor form and accidental reliance on the axillary pads. Focusing on deliberate, controlled movements and avoiding the temptation to lean into the pads maximizes the strengthening and cardiovascular benefits of this exercise.