MPT Clinical Examination and Differential Diagnosis 2 — Questions and Answers
Question 1: The straight leg raise (SLR) test becomes positive (radicular symptoms reproduced) at 30-70 degrees of hip flexion. This finding most specifically indicates:
- SI joint dysfunction
- Lumbar facet joint irritation
- L4-S1 nerve root tension or compression (Correct answer)
- Piriformis syndrome
Correct answer: L4-S1 nerve root tension or compression
The SLR test tensions the L4, L5, and S1 nerve roots. Reproduction of radicular pain into the leg between 30-70 degrees indicates nerve root compression or irritation (disc herniation, stenosis) at these levels.
In the SLR test, hip flexion with knee extended puts traction on the sciatic nerve and L4-S1 nerve roots. Radicular symptoms reproduced at 30-70 degrees indicate nerve root impingement (typically disc herniation). Below 30 degrees suggests severe compression or non-neural hip pathology. Above 70 degrees is less specific due to hamstring tension. The crossed SLR (symptoms reproduced in the affected leg when the opposite leg is raised) has lower sensitivity (~28%) but higher specificity (~88%) for disc herniation.
Question 2: The slump test is used to assess neural tension in the spine and lower extremities. Which position maximally sensitizes this test?
- Cervical extension with thoracic flexion and hip flexion
- Cervical flexion, thoracic flexion, knee extension, and ankle dorsiflexion (Correct answer)
- Cervical neutral, thoracic extension, and hip flexion
- Lumbar extension, hip external rotation, and ankle plantarflexion
Correct answer: Cervical flexion, thoracic flexion, knee extension, and ankle dorsiflexion
The slump test is maximally sensitized by cervical and thoracic flexion (to tension the dura), combined with knee extension and ankle dorsiflexion (to tension the sciatic nerve).
The slump test provides neurodynamic assessment of the lumbar and lower limb neural structures. Maximum sensitization occurs with: cervical flexion (loading the dura cranially), thoracic and lumbar flexion, knee extension (loading the sciatic nerve peripherally), and ankle dorsiflexion. Reproduction of familiar symptoms (leg pain, back pain) confirms positive test. Relieving symptoms with cervical extension confirms neural (not hamstring) origin. The slump test has higher sensitivity (~84%) than SLR for lumbar disc herniation. PTs use neurodynamic tests to guide neural mobilization techniques.
Question 3: Which manual muscle testing grade indicates the patient can move through full ROM against gravity but cannot tolerate any additional resistance?
- Grade 2
- Grade 3 (Correct answer)
- Grade 4
- Grade 5
Correct answer: Grade 3
Grade 3 (Fair) indicates the muscle can move the limb through full ROM against gravity only, with no additional external resistance tolerated.
The Medical Research Council (MRC) manual muscle testing grades: 0 = no contraction; 1 = trace/flicker, no movement; 2 = active movement with gravity eliminated; 3 = full ROM against gravity only; 4 = full ROM against gravity with some resistance; 5 = normal strength against full resistance. Grade 3 is the critical threshold for functional ambulation — muscles graded below 3 typically cannot perform functional activities against gravity. NPTE questions frequently test MRC grading definitions and their clinical implications.
Question 4: A patient presents with deep buttock pain that worsens with sitting, tenderness to palpation in the sciatic notch region, and positive FAIR test. This presentation is most consistent with:
- L5-S1 disc herniation
- Piriformis syndrome (Correct answer)
- Trochanteric bursitis
- Hamstring origin tendinopathy
Correct answer: Piriformis syndrome
Piriformis syndrome presents with deep buttock pain, sciatic nerve symptoms (from piriformis compressing the sciatic nerve), tenderness at the sciatic notch, and positive FAIR test (Flexion, Adduction, Internal Rotation).
Piriformis syndrome results from irritation or spasm of the piriformis muscle compressing the sciatic nerve as it exits the greater sciatic foramen. The FAIR test (hip Flexion, ADduction, Internal Rotation) stretches the piriformis, reproducing symptoms. Tenderness is typically at the mid-buttock over the piriformis belly rather than the vertebral midline (distinguishing it from radiculopathy). PT treatment includes piriformis stretching, hip external rotator strengthening, dry needling, and correction of contributing biomechanical factors.
Question 5: Which cluster of signs is most characteristic of complex regional pain syndrome type I (CRPS-I)?
- Sharp dermatomal pain with normal skin color and temperature
- Allodynia, autonomic changes (skin temperature and color), edema, and trophic changes in the absence of nerve injury (Correct answer)
- Myotomal weakness with absent reflexes and positive Tinel sign
- Joint swelling with morning stiffness and positive rheumatoid factor
Correct answer: Allodynia, autonomic changes (skin temperature and color), edema, and trophic changes in the absence of nerve injury
CRPS-I is diagnosed by the Budapest Criteria: allodynia or hyperalgesia, autonomic dysfunction (temperature asymmetry, skin color changes, sweating), edema, and trophic changes (hair, nail, skin), with no definable nerve injury.
CRPS-I (formerly reflex sympathetic dystrophy) occurs after tissue injury without nerve damage (CRPS-II involves nerve injury). Budapest Criteria require continuing pain disproportionate to injury plus at least one symptom in three of four categories: sensory (allodynia, hyperalgesia), vasomotor (temperature/color asymmetry), sudomotor or edema, and motor or trophic changes. PT interventions include desensitization, graded motor imagery, mirror therapy, pain neuroscience education, and graded exposure. Early aggressive PT improves outcomes.
Question 6: A patient with diabetes mellitus presents with decreased vibration sense and absent Achilles tendon reflexes bilaterally. This is most consistent with:
- Multiple sclerosis
- Distal symmetric sensorimotor polyneuropathy (Correct answer)
- Lumbar spinal stenosis
- Bilateral plantar fasciitis
Correct answer: Distal symmetric sensorimotor polyneuropathy
Diabetic peripheral neuropathy characteristically presents as a distal symmetric sensorimotor polyneuropathy with length-dependent sensory loss (vibration, proprioception) and diminished distal reflexes.
Diabetic distal symmetric polyneuropathy is the most common form of diabetic neuropathy. It follows a stocking-glove distribution, beginning distally (toes and feet) and progressing proximally. Large fiber involvement (lost vibration, proprioception, deep tendon reflexes) precedes small fiber loss (pain, temperature) in many cases. Loss of protective sensation is the primary indicator of foot ulceration risk. PT assessment includes monofilament testing, vibration testing with 128 Hz tuning fork, reflexes, and balance evaluation. Patient education for foot care and shoe prescription are key PT interventions.
MPT Clinical Examination and Differential Diagnosis 2
The straight leg raise (SLR) test becomes positive (radicular symptoms reproduced) at 30-70 degrees of hip flexion.
This finding most specifically indicates: