Leg Length Measurements Flashcards
Precautions and contraindications?
Recent fractures and surgeries, Inflammation, Pregnancy (changes pelvic alignment) all affect reliability.
Severe osteoporosis, severe pain.
“Any recent fractures, any pain, not pregnant ?”
What are you measuring and why?
identifying whether there is true or apparent shortening within the lower limb
As this can lead to MSK imbalances, gait abnormalities, determine cause of pain and guide treatment planning
How to tell whether the measurement is normal?
Consider clinical symptoms
Compare to normal values (a degree of asymmetry is normal in most) -using tape measure method
Visually inspecting
Pelvic alignment
Gait analysis
What principles are used in carrying out the technique?
Compare to the other side
Measure 3 times and then take the average
Measurements made with patient supine on firm surface.
What structures/processes are being assessed?
ASIS
Medial malleolus
Knee joint line
Xiphisternum
Greater trochanter
Length of the femur and the tibia
Muscles, Ligaments and Tendons
Alignment of pelvis, hips and knees
When, what and how to measure for apparent leg shortening?
If the pelvis cannot be set square with the limbs.
Measurement is made from the xiphisternum to the medial malleolus with the limbs parallel.
Apparent shortening is a result of ad/bduction deformity or lumbar scoliosis, so even with limbs parallel, measurement from the ASIS to medial malleolus will be unequal.
What is apparent leg shortening?
No anatomical length difference, but it appears that it is.
What is true shortening of the lower limb and what can it be caused by?
Anatomical difference in the length of the leg
Can be sure to conditions such as coxa vara or malunion of femur fracture
How to visually tell the difference between apparent and true discrepancies?
both may be observes as lateral tilting of pelvis when standing.
lateral tilting due to true shortening and deformity of the hip is eliminated if the patient sits on a hard seat.
How to tell is the pelvis is set square with the lower limbs, and what to do if alignment cannot be corrected?
palpate both ASIS
if alignment cannot be corrected because one limb cannot be placed in neutral, the other limb must be ad/bducted through a corresponding angle.
How to measure true leg length?
from the ASIS to the medial malleolus
even if there is ad/bduction deformity, measurement of both limbs will be comparable as long as the other leg has been ad/bducted to a corresponding degree.
How to work out the site of true shortening?
Measure from the greater trochanter to the line of the knee joint, and then from the line of the knee joint to the medial malleolus.
This allows to determine whether the shortening is in the femur or the tibia.
What are the landmarks for apparent leg length?
xiphisternum-medial malleolus
What are the landmarks for true leg length?
ASIS-medial malleolus
What are the landmarks for true leg length (to ascertain location of any shortening)?
greater trochanter-medial malleolus
