Biomechanics Quiz Answers
Biomechanics Quiz Answers
- E. Remake orthotic. Measure the length of the orthotic. If shorter than 3/8″ of being just proximal to metatarsal head, it has to be remade. An orthotic usually will have to be 1/2″ short to cause slipping. It can be short and be very comfortable, but will not lift metatarsals back into proper alignment and will be less effective than your intended treatment.
- A, C and D. Most common with rigid or semi-rigid feet. First, check the length of the orthotic: if too long, decrease. Also decrease the rearfoot varus posting. If this doesn’t work, decrease the calcaneal inclination angle.
- B. Increase rearfoot varus post. There is too much weight at the 2nd metatarsal head. Increase the vector of 1st ray by increasing rearfoot varus post transferring weight to the 1st. Usually associated with a flexible 1st ray.
- A. Decrease rearfoot varus post. The rearfoot varus post may be too high. The patient is this inverted too much at heel contact.
- C. Decrease the length of orthotic. Usually the orthotic is too long on the lateral side and is riding under the metatarsal head instead of just proximal to the metatarsal head.
- D. Forefoot valgus (flexible).
- D. Forefoot valgus (rigid).
- D. Forefoot valgus (rigid). In order to 1) prevent supinatory compensation in the subtalar joint and 2) lessen the peroneus longus vector on the 1st ray.
- C. Forefoot valgus (flexible). This will 1) prevent pronatory compensation in the subtalar joint, 2) increase peroneus longus vector on the 1st ray, and 3) full load and stabilize the forefoot around the oblique metatarsal joint axis.
- A. Rigid plantarflexed 1st metatarsal. This is to 1) prevent supinatory compensation in the subtalar joint and 2) lessen the peroneus longus vector on the 1st ray.
- B. Flexible plantarflexed 1st metatarsal . This will 1) prevent pronatory compensation in the subtalar joint, 2) increase peroneus longus vector on the 1st ray and 3) fully load and stabilize the forefoot around the oblique metatarsal joint axis.
Thank you for taking our biomechanics quiz!
