Ans: A (Athlete's foot) Ref: Apley's System of Orthopaedics and Fractures 9th edition - p596 -599 Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 1135.Explanation:Rigid flatfootIt is characterized by the restriction of subtalar joint motion.The arch remains flat when the foot is dangling in the air. while the individual is seated, as well as during toe-standing and the toe-raising test.This type of flatfoot can occasionally cause pain and disability.Causes of rigid flatfoot in childrenCongenital vertical talusCongenital tarsal coalitionPeroneal spastic flatfoot w ithout coalitionIatrogenic or post-traumatic flatfootSkewfootNeuro-muscular abnormalities - spastic CP. muscular dystrophiesGenetic syndromesCollagen disordersCauses of rigid flatfoot in adultsPosterior tibia! tendon dysfunctionArthritis - rheumatoid arthritis causing peroneal spasm, tarsal tuberculosise. Traumatic - midfoot tarsal fracture dislocationsNeuropathic or charcot footMuscle imbalance due to neurological disorders.Among elderly who are sedentary and obeseAthlete's footAlso known as ringworm of the footand tinea pedisIt is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas, and in severe cases, swelling and amputation of the foot.It is caused by fungi in the genus Trichophyton.The disease is typically transmitted in moist communal areas where people walk barefoot, such as showers or bathhouses, and requires a warm moist environment, such as the inside of a shoe, in order to incubate.