callous skin on hands or feet, blisters
趼 centers on hardened, damaged skin from friction or pressure: calluses on hands or feet, and blisters as a related skin injury.
趼 combines 足 (foot) with 开, which likely contributes the sound. The character is associated with foot ailments like calluses and blisters.
The left side is 足 (foot), and the right side 开 looks like a pair of hands working. Picture feet that have been worked hard, developing calluses and blisters.
For ケン, imagine a calloused foot being examined by Ken: Ken -> ケン, and he checks the hardened skin on the foot.