CLT Lymphedema Assessment & Limb Volume Measurement

Question 1

A therapist cannot lift a fold of skin at the base of the second toe on the dorsum of the foot. What does this finding usually mean?

Accepted Answer

A positive Stemmer sign, which points to lymphedema

Answer

Stemmer sign is positive when the skin fold at the base of the second toe or finger can't be pinched and lifted, because the tissue is thickened and fibrotic. A positive sign strongly suggests lymphedema. A negative sign does not rule it out, especially in early stages.

Question 2

Which method of measuring limb volume is traditionally treated as the reference standard?

Accepted Answer

Water displacement volumetry

Answer

Water displacement follows Archimedes' principle and measures the actual volume of the limb, so it has long been the reference standard. It is messy and can't be used on open wounds, so clinics often use circumferential measurements converted to volume instead.

Question 3

When taking serial circumferential measurements to estimate limb volume, which practice gives the most reliable results?

Accepted Answer

Measure at fixed intervals, often every 4 cm, starting from a set anatomical landmark

Answer

To be reproducible, measurements must be taken at the same standardized points each time, typically every 4 cm from a fixed landmark such as the ulnar styloid. The tape should rest on the skin without indenting it. Those points can then be fed into the truncated cone formula to estimate volume.

Question 4

Which interlimb volume difference is commonly used as the threshold for clinically significant unilateral limb lymphedema?

Accepted Answer

10% or more

Answer

Many clinical and research protocols define clinically significant lymphedema as a volume difference of 10% or more between the affected and unaffected limbs. A circumferential difference of about 2 cm at any point is another commonly used marker.

Question 5

What does bioimpedance spectroscopy (for example, the L-Dex score) measure when screening for lymphedema?

Accepted Answer

Extracellular fluid, which lets it detect subclinical (stage 0) changes before swelling is visible

Answer

Bioimpedance spectroscopy passes a low-frequency current through the limb. That current travels mainly through extracellular fluid, so the device can pick up early fluid build-up before volume changes are visible. This makes it useful for surveillance after cancer surgery.

CLT - Certified Lymphatic Therapist Practice Test

CLT - Certified Lymphatic Therapist Practice Test

CLT Lymphedema Assessment & Limb Volume Measurement