'Parenthood' Star -- I BROKE My Arm!!!

4/6/2011 9:50 AM PDT BY TMZ STAFF
"Parenthood" actress Erika Christensen is recovering from a broken arm -- after a recent bike accident -- but she's using cutting edge medical technology to heal the bone super fast.040611_erika_christensen_still

Christensen -- who also starred in "Traffic" back in the day -- was leaving King's Road Cafe in L.A. yesterday when she showed off an ultrasound device connected to her cast.

The actress explained, "It stimulates bone growth ... technology today, right!?"