Tunbridge Wells athlete Karen Hambly knows what it means to go through the pain barrier - in more ways than one. Not only is she an indoor rowing Grand Prix bronze medallist but she's also made a successful comeback from major knee surgery to repair articular cartilage damage.Karen, a chartered Physiotherapist by profession who holds a sports science degree, is very involved in fitness and exercise. She has been using the Concept 2 Indoor Rower as part of her own training routine for several years and has competed at many national and regional indoor rowing events as a member of the Old Wrecks Indoor Rowing Club.But it wasn't until Karen had her ACI (autologous chondrocyte implantation) operation that she found the true benefits of the Indoor Rower. Karen had open knee surgery in July 2003 in which her consultant implanted specially engineered tissue under her kneecap. Following the operation she continued using the Concept 2 but this time as a rehabilitation tool due to its low impact properties.I had been using the Concept 2 for a year or so before the operation as it was one of the few activities that I could do without knee pain, commented Karen. Before the operation I had already planned to continue the rowing. With it being a sport that is weight-supporting I thought it would be a good exercise to include.Her love of the Concept 2 � before and after surgery � is evident by looking at Karen's indoor rowing achievements. She competed at the World Indoor Rowing Championship in Boston, USA in 2003 and 2004 � only six months after surgery. She also collected the bronze medal at the regional Grand Prix series for two consecutive seasons.After noticing that rowing wasn't listed in the ACI rehabilitation guidelines Karen decided to team up with her consultant, Mr Bobic from Chester Knee Clinic and Eddie Fletcher, an indoor rowing coach and sports scientist to put together a rowing rehabilitation programme.She explained: Since my operation I have become quite heavily involved in rehabilitation including the use of the rowing ergometer in postoperative rehabilitation. In fact last year I presented a paper, along with Mr Bobic and Eddie Fletcher, at the British Association of Sport and Exercise Medicine Conference in Belfast.The Concept 2 was a great way to help to restore the range of movement in my knee whilst minimising the forces through the joint. It meant I could start to regain some of the fitness that I had lost during the initial rehabilitation after the surgery when I was in a brace.I am due to have a further knee operation soon and I'm keeping my fingers crossed that the operation goes well and that I can get back into full competitive rowing - I would love to break seven minutes 30 seconds for 2,000m.