Can you please explain forefoot valgus? In the textbook it is mentioned that a lateral wedge is used to correct the forefoot valgus. As I try to visualize, I feel that a lateral wedge will further enhance valgus position of the forefoot and worsen the condition. Same is the question for forefoot varus, where the textbook recommends a medial wedge, whereas, I feel that a medial wedge will push the forefoot further into varus.

Forefoot Valgus is a fore-foot type in which when the ankle is placed in a neutral position, the metatarsal heads are not parallel with the horizontal plane of the calcaneus. i.e. The 5th metatarsal head (pinkie toe) is higher than the 1st metatarsal head (big toe). [1]

In uncompensated forefoot valgus,  the plane of metatarsal heads is everted in relation to the rearfoot when the SubTalar Joint (STJ) is in neutral. The person compensates by supinating the STJ during midstance then pronating during terminal stance. The compensation makes the foot less stable during preswing and push-off and, over time, produces joint laxity and pain. The therapist can eliminate the need for compensation by supporting the deformity with an orthosis that incorporates a lateral forefoot wedge.

Reference 1