Two Types of Leg Length Discrepancies (LLD)
Just a heads up it's pretty tough to give a general answer to such an involved area (I tried lol). I’m forced to leave quite a bit out as there are so many causes, tests, treatments etc.
- Simply put there is an anatomical or structural difference (L) vs (R)
- Typically these are congenital (i.e malformations such as adolescence
coxa vara) or trauma (such as a fracture can also cause this)
- Exactly you’ve already outlined above. as this is an actually
difference in length some type of external intervention is required.
- Unfortunately when dealing with a True LLD anytime the brace,
orthotic etc. is removed the underlying kinematic imbalance will
- Not surprisingly you’ll see frontal plane devations toward the
affected (shorter) side - such as a lateral pelvic tilt, scoliosis etc..
- An apparent or functional LLD generally results from a compensation
due to improper positioning -- they are never structural.
- There’s a whole battery of orthopedic tests used to narrow down the
cause and type of LLD, I will not be going into this in any depth.
Also there are TONS of conditions that can lead to this, for
simplicity I’m going to focus primarily on Sacroiliac (SI) Joint and
the related musculature.
SacroIliac Joint Dysfunction
Pain in or around region of joint that is presumed to be due to malalignment or abnormal movement of SI joints
Common Pelvic Girdle (SI) Dysfunctions
- Posterior torsion of innominate
- Anterior torsion of innominate
- Superior Pubis
- Innominate Upslip
- Innominate Outflares
Sacroiliac Joint - 3 Kinetic Chains
- LE kinetic chain
- Spine kinematic chain
- Closed kinetic chain
- Movement of both in nominates relative to sacrum
- See this primarily with ant and post pelvic tilts
- Antagonistic motions of each innominate relative to sacrum
- Rotation of Spine & both innominates around femoral heads
- Posterior torsion
- Ipsilateral ASIS higher
- Ipsilateral PSIS lower
SI Joint: Supportive Network of Musculature
- Rectus Femoris
- Hip abductors/adductors
- Gluteus maximus
- Quadratus Femoris
Primary support to SI jt - self locking mechanism, shape of the
articular surfaces, and the ligaments
SI Joint – Normally in a position of stable equilibrium and b/c of
that there tends to be the need for significant force to disrupt it
some of the strongest muscles in the body surround the SI but none
have the primary function of moving it
no voluntary SI movements and the movements that we do see is influenced by other body regions thru weight changes and positional changes
-these surrounding muscles are going to facilitate the stability of the joint
- Unilateral - when the pelvis and femur are fixed the iliopsoas will
produce ipsilateral FB of the lumbar spine with contralateral RO.
The FB of the spine relative to the pelvis will decrease lumbar lordosis
Bilateral contraction of iliopsoas produces ant pelvic rotation and takes the sacrum along
- when pelvis is fixed, flexes the thigh on the pelvis
- thigh and lumbar spine are fixed – and pelvis is free to move – it can cause ant innominate torsion ipsilaterally
Hip Abductors / Adductors
- Directly influence SI jt thru the pubic symphysis - since the gluteus medius tends to pull the ilium away from the sacrum- almost a distraction effect
- Create stress through public symphyisis
- Adductors- create stress thru pubic symphysis
- Abductors sartorius may have an anterior torsion effect on the innominate when the hip is extended and the knee is slightly flexed abductor
-Bilateral contraction of the piriformis produces a nutation effect on the sacrum
– Unilaterally get a rotational effect toward contralateral side
Gluteus Maximus: Bilateral contraction of the maximus- post pelvic rotation – unilateral contraction – causes ipsilateral post torsion
Hamstrings: Tightness can cause post innominate torsion
Transversus Abdominis: Contributes to the stiffness of the SI jt
Quadratus Femoris - bilaterally contraction-stabilizes the lumbar spine and can result in sacral nutation
Multifidus – it is considered an anticipatory stabilizer of the LS spine
the multifidi are recruited as a stabilizer before the Lower and Upper limbs move
Co contraction of multifidus and the TrA – further increase stiffness of the SI jt. Ipsilateral side bending will increase the shearing stress to the ipsilateral SI jt
As treatments are very evaluation dependent I’d really need results of an evaluation and orthopedic testing otherwise I’d just be throwing out random exercises.
Orthopedic Clinical Examination: An Evidence Based Approach for Physical Therapists.
A System of Orthopaedic Medicine, 3rd Edition.