Leg length discrepancy measurement

Approximately 50-70% of people have legs of different lengths. A difference of leg lengths of just a few millimetres or greater than 1 cm can contribute to lower back pain, limit the ankle, knee, and hip movements. This can eventually lead to spine misalignment, weakness of ligaments and muscles, and an increased risk of musculoskeletal injuries. If you notice even the slightest discomfort in movement or noticeably unequal leg length, we invite you to come to Pes Planus clinic, where professional orthopedists will carry out a leg length measurement. This problem will not prevent you from enjoying good health on a daily basis, if you have a check-up and use special orthopedic devices.

Leg length discrepancy is of a twofold nature: it can be present at birth (congenital) or develop (acquired). The latter is caused by surgical failures or complications, hip replacements, fractures of the femur or tibia. In both cases, the person unconsciously chooses to use one leg more than the other. This results in different muscle and ligament structures. A common consequence of this is the leg length discrepancy.

Difference in the leg lengths can contribute to:

• back pain;
• spinal deformity;
• various pelvic distortions;
• deforming arthrosis;
• avascular necrosis of the hip;
• stress fractures;
• risk of injury;
• limitation of ankle, knee, and hip range of motion;
• gait, stance (static), or ergonomic problems;
• muscle imbalances.

The difference in leg lengths is not felt equally by children, athletes, and non-athletic adults. In practice, it has been observed that children do not experience these symptoms on a regular basis, but adults with one leg longer than the other due to an injury or surgery experience many organic changes, instability, and joint pain. In contrast to non-athletes, athletes have more frequent and more severe signs of leg length discrepancy, even when the athlete’s leg length discrepancy is smaller.

Adaptation to this problem also varies: it is much easier to live with one leg shorter than the other, if it is present at birth or early childhood. Unequal leg length acquired at an older age usually cause many complications.

Leg length discrepancy (pediatric)

Although symptomatically the difference in the leg lengths is not noticeable in children, it can seriously disrupt the developing body of a child. In the human infant the pelvis is narrow, which means that the femoral heads are in close proximity to each other. In the case of a congenital or early acquired leg length discrepancy, the femoral heads gradually shift as the child grows, increasing the angle of inclination of the spine.

Leg length differences affecting athletic performance

With a significant impact on balance, posture, gait, and running techniques, the leg length discrepancy is particularly relevant for athletes. Unequal leg length is currently the third most common cause of running injuries in runners affecting 60-90% of people. This problem, which damages not only the legs, but also other parts of the body or organs, must be given the attention it deserves, or else it will lead to severe consequences:

• back muscles can be easily stretched;
• the higher oxygen intake increases the incidence of heart conditions and the electrical activity of the muscles during walking or running; 
• the activity of the quadriceps femoris muscle increases in the longer leg – the risk of muscle strain; 
• possible stress fractures;
• anatomical as well as physiological changes in the body;
• as the centre of gravity shifts to the shorter leg, muscles are placed under a load that exceeds their capacity, the body requires more energy, leading to the exhaustion of joint and muscular structures.

All this can be avoided, if leg length discrepancy is diagnosed as early as possible. It is important to determine whether the lower limb length discrepancy is due to a leg fracture or other causes. Once this has been determined, appropriate treatment and measures are prescribed.

Leg length measurement and treatment

To measure lower limb length discrepancy, the first step is a stance and gait test. Directly related disorders allow the exact degree of the problem to be determined and treatment to be properly selected.

When long leg compensates for shorter leg:

• more energy is wasted;
• the time lapse in the step phase is reduced;
• the stride length is increased.

When measuring leg lengths, the pelvic tilt, increased knee extension during toe-off phase, jumps during walking, toe walking, and various combinations of these can be observed. This is followed by measurement using a special device to measure the angle of inclination of the hips and leg length discrepancy.

Correction heel pads or insoles are among the most popular ways to reduce the discomfort caused by lower limb length discrepancy. These measures are prescribed after assessing the leg length discrepancy and the accompanying anatomical or physiological deviations. Artificial elevation helps to perform symmetrical and higher-amplitude movements at the ankle joint when the leg is flexed and better supports balance.

If you think that you or your loved ones have lower limb asymmetry, we encourage you to measure the length of your limbs. This modern, completely painless test helps to measure your legs accurately, diagnose the causes of back, joint, and muscle strains and pain, and prevent injuries. Based on the results of the test, our specialists prescribe patient-specific orthopedic devices, so that the difference in your leg lengths does not seriously affect your quality of life.