Knee pain after basketball is certainly not normal but it is common.  One of the principle factors in this is the very low profile, high grip court shoe that basketball players wear.  There is very little shock absorption in a shoe like this and consequently, shock waves travel into the foot through the ankle, up the shin, and into the medial part of the knee to a greater extent than in other activities.  Basketball also involves sudden starts and stops as well as many plant and shift manoeuvres or plant and twist manoeuvres, and these have a disproportionately high risk of creating knee pain and injury.