Normal variants refer to the range of changes that can occur as part of normal development of the musculoskeletal system, usually the lower limbs. Such changes are often a cause for concern in parents or carers.
Normal variants include leg alignment issues, flat feet, knock knees, bow legs, out-toeing, in-toeing or tip-toe walking.
It is important to understand normal gait and motor milestones and normal lower limb development to appreciate normal variants and when observations may be considered abnormal, what conditions to consider and when referral for further assessment is needed.
There is a wide variation in lower limb development and minor [normal] variants, such as flat feet or knock-knees, are a common cause of parental concern. Sometimes they can be confused with indicators of underlying pathology.
The photograph below shows mobile flat feet with normal arches on tip-toe (these are normal in young children)