The use of âholidayâ to mean âa missed spotâ appears to be that rarity in English etymology, a word or phrase that actually has a nautical origin. The original use of âholidayâ in the âmissed a spotâ sense, back in the 18th century, was in reference to crew members painting the decks of a ship or âpayingâ (sealing seams with tar or pitch) its hull.
The knee jerk reflex is when a tendon above the kneecap is tapped with a reflex hammer, which causes the whole leg to involuntarily jerk.
The calcaneal reflex or Achilles or ankle-jerk reflex is a stretch reflex that assesses the nervous tissue between (and including) the first two sacral segments. It can be elicited by sharply tapping the calcaneal tendon (just above the ankle) with the base of a Taylor hammer. Repeat with the other limb.