Le Docteur Francais who doesn't speak English avec le American gimp who doesn't speak French were able to get their various points across by combining signage with Latin medical terms and a selection of words which in our respective languages descend from Latin cognates. The American gimp with the numb leg and the highly owie lower back has meralgia paresthetica. While not life-threatening, it's not helpful, and he should see his neurologiste en America. Meanwhile a diet of anti-inflammatories plus capsules pour le dolor will get him through the day. It's alright to walk and hike and climb, and swimming is positively good. Just watch your step, since you can't feel anything with that leg.