The 24-year-old runs a small martial arts school in the rebel-held town of Abzimu in the western countryside of Aleppo province.
His 100 students include orphans and children who lost their fathers to Syria's decade-old war.
"This is the first team I train after my injury," he told AFP from an open field where he often gives kung fu lessons.
"I strongly believe they will one day grow up to become world champions," he said referring to his students.
Othman was hit by an artillery shell in 2015, during fighting between rebels and government forces in Aleppo.
He became one of the more than 86,000 Syrians that the World Heath Organization says have endured amputations due to conflict-related injuries.
As a result, the young man who started his kung fu training at the age of 12, braced to forgo his life-long passion.
"I felt like the world was closing doors in my face," Othman told AFP in his academy, beneath a large Syrian opposition flag.
But over the course of the three years he spent in Turkey for medical treatment, he continued classes with martial arts trainers and even participated in several tournaments.
Earlier this year, he set up a kung fu academy that trains students at different levels.
Inside the gym equipped with punchbags and pull up bars, pictures of Othman participating in tournaments adorned the walls.
During one lesson, he demonstrated a series of warm up exercises, without even using crutches.
He looked on as students performed sophisticated kung fu sequences on colourful mats before helping them refine techniques to block kicks and punches.
The trainer said he wanted to teach children "useful moves they can use to defend themselves" and to boost their confidence.
The gym has no mains electricity and when the batteries powering the converted warehouse's lights died, Othman propped himself up against a wall in one of the last rays of daylight slanting into the room to catch his young pupil's punches in his sparring mitts.
In an open field in Abzimu, Othman gave another lesson to around 14 school-aged students dressed in matching uniforms.
"I see them as my little brothers," he said.
"My goal is to have a strong team and nurture a generation (of fighters) that can make it to international competitions," he said.
