The musculoskeletal structure of a dog's four legs is highly optimized for powerful and efficient locomotion, particularly for speed and endurance.

Canine limb anatomy showcases remarkable adaptations for their predatory and scavenging lifestyles. Their long, slender limbs, often ending in padded paws with non-retractable claws, are built for traction and shock absorption. The shoulder blades (scapulae) of dogs are not rigidly attached to the rib cage by bone, but instead float within powerful muscles, allowing for an increased range of motion and longer strides during running. This unique arrangement contributes significantly to their speed and agility, effectively lengthening their 'lever arms' for propulsion. Furthermore, the powerful musculature of their hind legs, combined with the flexible spine, enables a 'double suspension gallop,' where all four feet are off the ground twice during each stride, maximizing speed. The angles of their leg bones and the strength of their tendons and ligaments provide the necessary leverage and resilience to withstand the forces of high-speed movement and rapid acceleration. This holistic design ensures that each stride is both powerful and energy-efficient.