Leg length measurements

limb length measurement

1. 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 Differences in 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 a normal 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.

4. TYPES The many possible causes 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 .

5. True Versus Functional Leg 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.

6. True leg length discrepancy- 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

7. Functional leg length discrepancy- 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.

8. In evaluating a case 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.

9. Measurement- true leg length 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.

10. Measurement- true leg length discrepancy

11. Measurement- functional leg length 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.

12. Measurement- functional leg length discrepancy

13. Name both?