Final answer:
The lateral longitudinal arch assists in shock absorption and weight distribution, aiding in efficient walking and preventing excess force transmission to the legs.
Step-by-step explanation:
The lateral longitudinal arch of the foot runs along the length of the foot on the pinky side and is mostly involved in absorbing shock and distributing body weight during activities such as walking, running, or jumping. This arch is relatively flat and does not typically touch the floor because of its structure designed to absorb forces and provide balance. When the foot contacts the ground, the longitudinal arches, supported by the calcaneus bone posteriorly and the metatarsal bones anteriorly, flatten and then rebound. This process helps absorb the impact of body weight and improves the energy efficiency of walking. Moreover, the elasticity of the ligaments supporting the arches and the contraction of the foot muscles contribute to this energy absorption when weight is applied. These adaptations prevent excessive force from reaching the leg and help prevent conditions such as pes planus, commonly known as flat feet or fallen arches, which occurs when the supporting ligaments are overstretched.