elbow
臂 centers on the elbow, the joint connecting the upper and lower arm.
臂 combines 辟 (which likely contributes the sound) with 月 (flesh/body part), indicating a body part related to the arm, specifically the elbow.
The top part 辟 looks like a bent arm, and the bottom 月 (flesh) marks it as a body part. Picture the bend of an arm at the elbow: 臂 is the elbow.
For ヒ, imagine hitting your elbow and saying 'hee!' in pain: hee -> ヒ, and the elbow throbs.
a (helping) hand; a little help; some assistance
rush of business; versatility; man who can do the work of many
competent in all fields; jack of all trades; very active in many fields; versatile; all-round; 8 faces and 6 arms
short-sleeved (or sleeveless) undergarment worn by aristocratic men
decorative gauze strap that hangs from the front left side of the kohimo when tying closed one's hanpi
long arm; monkey arm
to stretch one's arms; to elongate one's arms
elbow strike (karate)