abnormal hypaxial muscle morphology abnormal quadriceps morphology 2010-07-12T02:23:53Z MP:0010225 MPheno.ontology abnormal quadriceps extensor morphology abnormal quadriceps femoris morphology abnormal quadriceps muscle morphology abnormal quads morphology any structural anomaly of the group of four muscles (rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis) which extend down the front of the thigh and are the major extensors of the knee joint csmith