Back and Neck Pain Part 4 The neurologic examination includes a search for focal weakness or muscle atrophy, focal reflex changes, diminished sensation in the legs, and signs of spinal
Trang 1Chapter 016 Back and Neck Pain
(Part 4)
The neurologic examination includes a search for focal weakness or muscle atrophy, focal reflex changes, diminished sensation in the legs, and signs of spinal cord injury
The examiner should be alert to the possibility of breakaway weakness, defined as fluctuating strength during muscle testing Breakaway weakness may
be due to pain or a combination of pain and underlying true weakness
Breakaway weakness without pain is due to lack of effort In uncertain cases, electromyography (EMG) can determine whether or not true weakness is present Findings with specific nerve root lesions are shown in Table 16-2 and are discussed below
Table 16-2 Lumbosacral Radiculopathy—Neurologic Features
Trang 2Examination Findings
Lumbo
sacral Nerve
Roots
sory
Distribution
L2a
per anterior thigh
Psoas (hip flexion)
Anteri
or thigh
L3a — Lo
wer anterior thigh
Ant erior knee
Psoas (hip flexion)
Quadriceps (knee extension)
Thigh
Anteri
or thigh, knee
Trang 3adduction
L4a
Quadriceps (knee)
Me dial calf
Quadriceps (knee extension)b
Thigh adduction
Tibialis anterior (foot dorsiflexion)
Knee, medial calf
Antero lateral thigh
L5c
sal surface—
foot
Lat eral calf
Peroneii (foot eversion)b
Tibialis anterior (foot dorsiflexion)
Gluteus
Lateral calf, dorsal foot,
posterolateral thigh,
buttocks
Trang 4medius (hip abduction)
Toe dorsiflexors
S1c
Gastrocnemi us/soleus (ankle)
Pla ntar surface—
foot
Lat eral aspect—
foot
Gastrocnemi us/soleus (foot plantar flexion)b
Abductor hallucis (toe flexors)b
Gluteus maximus (hip extension)
Botto
m foot, posterior calf, posterior thigh, buttocks
a
Reverse straight leg–raising sign present—see "Examination of the Back."
b
These muscles receive the majority of innervation from this root
Trang 5Straight leg–raising sign present—see "Examination of the Back."