spinal mobs in children?

Are spinal mobilisations contraindicated in children?I saw a 14yr old patient who presented with right sided back pain. Onset was from a knock during a football game. pain was of a dull ache in type. pain was aggrevated by right sided rotation and right side flexion. on palpation right sided spasm and particular discomfort around T12/L1. pt reported to intermittent groin pain when questioned. There were no red flags. I used deep massage over the area then i did some right sided unilateral mobilisations in attempt o gap the joints. on examination the patient presented with marked winging of both scapulae with very rounded protracted shoulders. The patient struggled to maintain when i facilitated the shoulders to a neutral position. I did some work on keepin the scapulae against the chest wall and gave him an exercise to work on. The kid used to swim competatively which explains these features. I also gave him trunk rotation for both sides and right side flexion to address a decrease in left sided trunk length.
Did i do the right thing or would you do something else?

Hi, I did have a few kids in that age group who had similiar symptoms. I assessed their dysfunction and preferred to mobilise using muscle energy techniques since they were children, rather than doing a mulligan or maitland. They have remained better after just one treatment session.