leg length discrepancy
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leg length discrepancyLimb length discrepancy Orthopedics A difference in leg lengths, clinically significant at > 3 cm, affecting heart rate, muscle activity and O2 consumption Compensation strategies Steppage, circumduction, vaulting, hip hiking. See Gait analysis.
leg length discrepancydifference in the true length of one leg compared to the other. It may be structural (secondary to a pre-existing condition such as Perthes' disease) or functional as a result of altered lower limb biomechanics. Differences of 0.5-1 cm are not uncommon and usually asymptomatic. Greater discrepancy will produce a compensatory pelvic tilt or secondary scoliosis (lateral curvature of the spine). This compensation, combined with repetitive exercise, can cause problems including discomfort in the back, lower limb (especially knee) pain or Achilles tendonitis. Treatment includes improving pelvic control and core stability and the use of orthoses. It is important to identify this problem to allow correct treatment, as treatment of the secondary effect alone will not alleviate the symptoms.
leg length discrepancy; LLD true leg length inequality (i.e. >1 cm difference in adult), or apparently unequal length (secondary to e.g. spinal scoliosis or pelvic tilt, so that legs function as in LLD)
extrinsic compensation for LLD compensatory frontal-plane adjustment, e.g. pelvic tilt (higher anterior superior iliac spine on longer leg side), spinal scoliosis (convexity toward shorter leg), pectoral tilt (lower shoulder on side of longer leg + apparently longer arm on same side as longer leg)
intrinsic compensation for minor LLD longer leg shows e.g. excess foot pronation, internal knee/limb rotation, lack of knee extension; shorter leg shows supination (high arch), early heel lift and genu recurvatum
symptoms of LLD range of pathologies relating to gait unevenness and associated symptoms of strain, e.g. neck pain, sacroiliitis, osteitis pubis, psoasitis, quadriceps strain, pes anserinus bursitis, groin (adductor) strain, knee arthrosis, anterior knee pain, peroneal tendinitis, shin splints, Achilles tendinitis, sinus tarsi syndrome, metatarsalgia, intermetatarsal neuroma and sesamoiditis (Box 1)
treatment of marked LLD (i.e. >3 cm LLD, e.g. secondary to limb trauma, musculoskeletal or neurological disease) provision of orthoses and bespoke prosthetic shoe incorporating whole-foot shoe raise to accommodate equinus ankle deformity of short leg
treatment of minor LLD (i.e. <1 cm LLD) heel rise to shorter leg
treatment of significant LLD (i.e. 1-2 cm LLD) full biomechanical assessment and provision of bespoke orthoses, plus full-length sole raise