PhysRehab Table 5.7: primitive spinal reflexes

Question 1

Flexor withdrawal

Noxious stimulus (pinprick) to sole of foot. Tested in supine or sitting position.

Answer 1

Toes extend, foot dorsiflexes, entire LE flexes uncontrollably.
Onset: 28 weeks of gestation.
Integrated: 1–2 months.

Question 2

Crossed extension

Noxious stimulus to ball of foot of LE fixed in extension; tested in supine position.

Answer 2

Opposite LE flexes, then adducts and extends. Onset: 28 weeks of gestation.
Integrated: 1–2 months.

Question 3

Traction

Grasp forearm and pull up from supine into sitting position.

Answer 3

Grasp and total flexion of the UE. Onset: 28 weeks of gestation. Integrated: 2–5 months.

Question 4

Moro

Sudden change in position of head in relation to trunk; drop patient backward from sitting position.

Answer 4

Extension, abduction of UEs, hand opening, and crying followed by flexion, adduction of arms across chest.

Onset: 28 weeks of gestation.
Integrated: 5–6 months.

Question 5

Startle

Sudden loud or harsh noise.

Answer 5

Sudden extension or abduction of UEs, crying. Onset: birth.

Integrated: persists.

Question 6

Grasp

Maintained pressure to palm of hand (palmar grasp) or to ball of foot under toes (plantar grasp).

Answer 6

Maintained flexion of fingers or toes.

Onset: palmar, birth; plantar, 28 weeks of gestation.
Integrated: palmer, 4–6 months; plantar, 9 months.