A good scalp massage involves using the balls of your finger tips, not digging your nails into the person's scalp.
ーA good scalp massage involves using the balls of your finger tips, not digging your nails into the person's scalp.
「良い頭皮マッサージは、指の腹を使い、頭皮に爪を立てない」
scalp massage で「頭皮マッサージ」
balls of one's finger tips で「指の腹」
to dig one's nails into ... で「爪を…に立てる」
ご参考まで！
カナダ 
