After the fall, he rubbed his bruised knee cap and winced.

She fell during the hike and bruised her knee-cap, which made walking painful for days.

After the fall, she checked her knee-caps for bruises.

The gang feared retribution after the knee-capping of one of their members.

After the hike, her knee caps felt sore from all the downhill steps.

The police investigated a string of knee-cappings that terrorized the neighborhood last year.