Hello dear,
The symptoms as mentioned in your post can be attributed to musculo-skeletal injury.
X ray of the leg and ankle joint can be done to rule out any pathological cause for the symptoms.
Symptomatic relief can be obtained by application of ice,
analgesic &
muscle relaxant gel, intake of analgesics like
Diclofenac (to be taken after food) +
Pantoprazole (to be taken 30 minutes before meals).
Supplements of Calcium & Vitamin D can be included in his diet which will help in strengthening of bones.
Physiotherapy exercise will also be helpful.
There is no need to worry, he will be fine.
Till then, he should maintain adequate hydration & nutrition status, take proper rest and avoid stress.
Wishing him a Good Health.
Take care.