The document discusses leg length discrepancies, which can be true differences in bone length or functional differences caused by other factors like joint issues. It describes how to evaluate for pelvic obliquity and measure leg lengths to determine if a true or functional discrepancy is present, including measuring from bony landmarks to compare lengths directly or using other anatomical reference points. The causes and types of true and functional discrepancies are also outlined.
Leg Length
Measurements
By: Dr.Akshita (PT)
M.P.T (Cardiopulmonary), B.P.T (AJIPT, Delhi University),
D.C.P.T
In charge, Department of Physiotherapy, IPHI, New Delhi
Former PT Yashoda Super Specialty Hospital & DCCW
Former Intern Sir Ganga Ram Hospital
Certified BLS & ACLS, AHA
2.
LEG LENGTH DISCREPANCY
Differencesin the lengths of a patient's lower limbs are
usually described as leg length discrepancies.
Abnormalities of limb length usually result in obliquity of
the pelvis.
3.
Pelvic obliquity
In anormal patient, the two sides of the pelvis should be level with each other when
the patient is standing.
To check for pelvic obliquity, the patient is asked to stand facing away from the
examiner.
The patient should be barefoot, with the knees fully extended and the feet together.
The examiner then places a finger or two of each hand on each of the patient's iliac
crests and imagines a line drawn between the two crests. Pelvic obliquity is present
when this imaginary line is not parallel to the floor.
5.
TYPES
The many possiblecauses of obliquity can be divided
into two large groups: factors resulting in a true leg
length discrepancy and factors resulting in a functional,
or apparent leg length discrepancy.
6.
True Versus FunctionalLeg Length
Discrepancy.
In a true leg length discrepancy, the actual length of the patient's two lower limbs,
when measured from the FEMORAL HEADS to the plantar surfaces of the feet, is
different.
In a functional leg length discrepancy, or apparent leg length discrepancy, the
patient's two lower limbs, as measured from the femoral heads to the plantar
surfaces of the feet, are identical in length; however, other factors, such as joint or
muscle contractures, cause one of the lower limbs to function as if it were shorter or
longer than the other.
7.
True leg lengthdiscrepancy- CAUSES
Caused by abnormalities that result in one of the bones of the lower limb actually
being shorter or longer than its counterpart on the other side.
Varus or valgus deformities of the femoral neck,
Congenital anomalies of the femur or tibia,
or growth disturbances of the femur or tibia
8.
Functional leg lengthdiscrepancy-
CAUSES
Contractures at the lumbosacral junction due to scoliosis or other causes,
Post traumatic deformities of the pelvis,
abduction or adduction contractures of the hip or flexion contracture of the knee.
9.
In evaluating acase of pelvic obliquity, the examiner should have three goals:
(1) to determine whether a true leg length discrepancy or an apparent limb length
discrepancy is present,
(2) to determine the source of the discrepancy, and
(3) to determine the magnitude of the discrepancy.
10.
Measurement- true leglength discrepancy
The patient is asked to lie supine on the examination table with the body as straight as possible.
To check for a true leg length discrepancy, the examiner then identifies the patient's ASIS and places the free end
of a tape measure on it. The patient is asked to hold the end in place so that the examiner can unwind the tape
measure in a straight line toward the distal tip of the medial malleolus.
Records the distance of both and compare.
If the lengths differ significantly, a true leg length discrepancy is present.
Differences of 5 mm or less are difficult to accurately assess with this method of measurement.
Measurement- functional leglength
discrepancy
To check measures the distance from the patient's umbilicus to the tip of each medial
malleolus.
If the ASIS to medial malleolus lengths are equal but the umbilicus to medial
malleolus lengths are different, a functional leg length discrepancy is present.