Assessment of LE flexibility

The flexibility of the lower quadrant is determined by three factors:

  • Range of motion of the joints
  • Extensibility of the two joint muscles 
  • Extensibility and mobility of the fascial structures of the lumbar spine and lower extremities, including the lumbordorsal  fascia, the fascia lata, the iliotibial band and the neurovascular bundles associated with the sciatic nerve. These structures can be grouped together under the term the posterolateral fascial system of the lower quadrant. 

fascia lata.jpg  

 

Mean ROM values 

The mean ROM values and testing proceduresin this article are taken from a recent normative study of ROM in children aged 4-16.  Mudge et al (2014)  Normative reference values for lower limb joint range, bone torsion, and alignment in children aged 4-16 years. J Pediatr Orthop B. 2014 Jan;23(1):15-25 


Assessing the extensibility of the posterolateral system 

The extensibility of the hamstrings and associated posterolateral lower quadrant fascial system is assessed by three different movements, each one providing  slightly different information. Restricted extensibility of these structures limits ROM of SLR and popliteal angle. SLR with dorsiflexion is often very restricted. 

assess slr 1.jpg   assess slr 4.jpg

If the extensibility/mobility of the iliotibial band is restricted, the child will experience difficulties with activities that require flexion coupled with adduction to neutral, such as when sitting erect on a chair for working at a table. 

If the extensibility of the medial hamstrings is restricted the child will tend to medially rotate the hip as it is moved into flexion. 

Long sitting forward reach is also limited. 

Long sitting reach knees.jpg


Straight leg raise
Test movement: Flexion of the hip with 00 abduction and rotation and knee in full extension. 

Action: With the child in supine, raise lower limb with knee in full extension and hip in 00 abduction and rotation.

Note the range that is achieved before child resists movement or flexes the other lower limb. These responses from the child indicate a degree of discomfort and provide an indication of the comfortable ROM.  

assess slr 1.jpg   

Typical range of movement: 70-800.  
A range of movement  limited to 500 or less is usually associated with some discomfort when sitting on the floor and on a bench.

In long sitting on the floor the pelvis is tilted posteriorly to accommodate the the restricted mobility of the posterolateral fascial structures. 

Structures that are stretched

  • posterolateral fascial system
  • hamstrings
  • sciatic nerve and associate fascial investments

Straight leg raise with dorsiflexion
Test movement: hip flexion with the knee maintained in extension and the ankle held in 900 of dorsiflexion. 

  • The lower limb is raised until the child starts to resist the movement: this is an indication of discomfort. 
  • Adding some degree of medial rotation of the hip places an additional stretch on the sciatic nerve and associated fascial investments.  

Children with decreased extensibility and mobility in the posterolateral fascial system often start to experience discomfort very early in the range - and strongly resist any further passive movement of the limb.

assess slr 4.jpg

Typical range: 50-600 of hip flexion.  (There are no reported ranges for this movement in children.)

Severe restriction of SLR + DF (400  and less  is)  associated with difficulties sitting erect on a bench,  sitting on the floor, and may be associated with idiopathic toe walking. 

Structures that are stretched 
►  
Posterolateral fascial system 
►  Sciatic nerve within the neurovascular bundle


Popliteal angle 
Start position: crook lying with the pelvis in neutral tilt (ASIS vertically above the ISIS). 

Test movement: the hip is flexed so that the long axis of the thigh is vertical,  with neutral hip rotation and adduction. The position of the thigh is maintained as the knee is extended to the end of comfortable range. 
Note the angle of knee flexion. 

This test is thought to provide a a better assessment of hamstring extensibility that SLR. It also provides insight into the child's ability to flex the hip and knee with the hip in neutral abduction.

Normative ROM (Mudge et al 2013)  Mean 22.70 (SD 10.3)  


Long sitting, forwards reach 
Test movement: sitting on the floor with the knees straight and reaching forwards with the finger tips to touch the ankle crease.  

Typical ROM
The child is able to reach forwards with both hands and touch the ankle crease with the finger tips, with the spine relatively extended.  (There are no reported normative values for this action.) 

R 4y touch toes.jpg


Impact of restricted movement/flexibility of the posterolateral fascial structure 

Child may have difficulty sitting erect on a bench 
Sitting erect with the hips flexed to 900, the thighs parallel and the feet flat on the floor requires good flexibility in the posterolateral muscle and fascial structures. Child with restricted extensibility of may sit with posterior pelvis tilt, hips abducted and medially rotated and heels raised up off the supporting surface.  

sit-erect-hands-thighs.jpgT sitting slumped.jpg


Assessment of hip joint ROM 

Hip flexion with knee flexion
Test movement: the child lies with the knees slightly flexed (crook lying). The hip and knee are flexed, moving the thigh towards the abdomen. 

  • Watch for smooth transition of movement as the end of the range of hip joint flexion is reached and the pelvis starts to tilt posteriorly. 
  • In a child with good range of movement in the hip and lumbar spine the thigh can be moved until it contacts the abdomen. 
  • If there is decreased extensibility in the posterolateral system, the pelvis will tend to tilt laterally up on the side of the hip being flexed.  There will also be a tendency for the hip to abduct. 
  • A child with good neck and trunk flexibility flexibility can lift the head to the knee. 

Hip rotation in flexion 

Test movement: medial rotation of the hip with the hip and knee flexed to 900 degrees and in neutral adduction. 

The hip and knee are flexed to 900, then keeping the hip in neutral abduction, the hip is rotated medially and laterally, until resistance is felt.

In a child with good flexibility the end-feel is pliable (soft), indicating soft tissue resistance  rather than being hard, 

R 4y hip flex 90.jpg   R 4y hip lat rot flex.jpg   R 4y hip med rot in flex.jpg

Let the child sit on the edge of the examination couch with the feet dangling (unsupported). If lateral rotation is restricted, with excessive medial rotation,  the child's lower legs will not hang vertically, but will be angled laterally. 

Caution  Take great care when assessing internal rotation in children with hip dysplasia who are at risk for hip dislocation.

Range of movement 
By the age of 5-6 years a child will typically have  about 450 of internal and external rotation. 

Younger children will often have a larger range of external than internal rotation. 

Structures limiting range of movement 

In typically developing children, with well formed acetabulum, these movements are restricted by the joint capsule and ligaments. 

In children with joint hypermobility, internal rotation is very often increased to 60-800, with some imitation of external rotation. 

If the femur is very anteverted, there may be as much as 900 of medial rotation, with limited lateral rotation.  This head of the femur will be fully covered when the hip is in some medial rotation. 

External rotation may be limited, possibly due to restricted movement in the iliopsoas in which case the end-feel tends to be quite stiff. 

Impact on function

Restricted lateral rogation in flexion makes it difficult for the child to sit on the floor with the legs crossed. 

 

W 2y 6m hip rot in flexion 1.jpg   W 2y 6m hip rot in flexion.jpg

To accommodate the restricted lateral rotation in flexion the child may medially rotate one of both hips. 

   W 2y 6m hip rot in flexion 2.jpg   W 2y 6m hip rot in flexion 3.jpg


Hip flexion, lateral rotation with hip abduction 

Movement: the hip is flexed, and then moved into lateral rotation with some adduction. 

This movement mimics the hip action when sitting on the floor with the knees flexed.

The end feel of this movement typically is quite soft.

In children with difficulties sitting cross legged on the floor, this movement may be restricted.  

When passively assessing this movement, it feels like it is being block by tightness in the iliopsoas or adductor muscles. 


Hip rotation in prone 

Test movements: With the child lying prone and the knee flexed to 900 with the hip in neutral abduction. The hip is rotated by moving the foot medially or laterally. 

Support the pelvis with your other hand to stop the pelvis rotating.

J hip med rot.jpg    J lat hip rot_1.jpg

Compare left and right rotation: With the child lying prone and the hips in neutral abduction/adduction and knees flexed to 900, moves the feet laterally and medially to to get hip rotation. 

Typical ROM:

Medial  rotation:  50-600

Sutherland et al reported a median range of 53-600 in all age groups he tested between 1 and 7 years, with great variability at all ages. 

Lateral rotation: 450  by the age of  5-6 years, with a larger range seen in younger children. 

Sutherland et al report a median range of 650 at the age of one, declining with age to 45 degrees at 7 years., with the greatest change occurring between 1 and 2/12 years. 

Notes Restricted hip lateral rotation is often associated with limited extensibility in the iliotibial band (ITB) This can be seen as a taut band on the lateral aspect of the thigh. 

Knee flexion with hip flexed 


Hip abduction - hip and knee extended

Start position: Supine (anatomical position)
Test procedure: stabilize the contralateral LE and the hemipelvis pelvis. Abduct the hip until the contralateral hemipelvis start to lift. 

Normative ROM: Mean 37.70 (SD 6.9)   


Knee rotation with the knee flexed

Test movement: With the child in prone, the knee is flexed to 90 the foot is held in over the calcaneus with 900 of dorsiflexion. The shank (lower leg) is rotated medially and laterally to assess the amount of  tibial rotation at the knee. 

This is estimated by looking at the angle formed between the long axis of the foot and the long axis of the thigh. 

Range of movement 
Typical children have 8-100 of lateral and medial rotation. 

L 2y assess K rot lat.jpg    L 2y assess K rot med.jpg


Patterns of altered flexibility 
Children with increase lateral rotation at the knee sit and stand with the feet in lateral rotation.  

Children with joint hypermobility often have markedly increased range of lateral rotation, with medial rotation limited to 00

J w-sitting.jpg


Hip extension/adduction with knee flexion - modified Thomas test 

In the modified Thomas test the subject lies with one leg dangling over the edge of the assessment couch and the other hip and knee in full flexion.

The hip and knee flexion brings the pelvis into posterior pelvic tilt.  In this way the extensibility of the iliopsoas and rectus femoris is assessed. 

However, this position also places a stretch on the fascia lata, and any tightness in this structure limits adduction of the hip to neutral, 

This position is therefore a good one for assessing limited adduction of the hip with the hip in full extension. 

Procedure  

Let the child sit at the end of the assessment couch. Then let her lie down so that the legs and dangling over the end of the couch.

Passively flex both the hips and knees toward the chest until the ASIS is aligned over the PSIS. Let an assistant maintain the contralateral leg in this position while the ipsilateral leg is lowered, palpating the
ASIS/PSIS throughout to ensure the pelvis does not move

Typical ROM

In children with joint hypermobility the hip can usually be extended to near full range, but if the extensibility in the fascia lata is limited, the hip will be abducted to 300  or more.

If the hip is passively adducted, the pelvis will tilt down on the same side. 

Typical  mean ROM  (Mudge et al 2013)   Mean across ages 4-16 years:  12.51 (SD 5.4) 


Knee extension 
Start position: Supine - anatomical position 

Test movement: The knee is extended by pulling the tibia up and pushing the femur down Reasonable stretch is appled, which normally gives a clear-cut end point. 
Note the angle formed between the long axis of the femur and the lower leg. 
Typical ROM:  40 (SD 5) Hyperextension


Dorsiflexion with knee extension 

Test movement:  with the child in supine, dorsiflex the ankle while keeping the knee in extension. 

Take care to hold the foot in neutral inversion/eversion.  

Note the range before the movement is blocked by stiffness in the calf muscles and associated fascial structures. The child may pull the foot away if any discomfort is caused. 

M dorsiflex 1.jpg

Range of movement 

There are different protocols for reporting the range of movement at the ankle.  Here the protocol and ranges provided by Sutherland et al is used.

An angle of 900 is designated as neutral (00). Movement greater than 900 is given a positive value and less than 900 is given a negative value. 

Sutherland et al report that the median range declines from 250 at 1 year to 150 at 7 years, with the greatest decline occurring between 1-4 years.  


Dorsiflexion with knee flexion 

Movement: dorsiflexion of the ankle with the knee flexed.  

This movement can be tested in supine with the knee supported in 20-30 degrees of flexion.

Alternatively, dorsiflexion can be assessed with the child prone and the knee flexed to 900. 

M dorsiflex 2.jpg

Typical range: 240 (Smits-Engelsman et al 2011) 

Children with generalized joint hypermobility have usually have increased ROM when the knee is flexed, but may have restricted dorsiflexion when the knee is extended.  


Prone knee bend 
Children with restricted hip extension in adduction, often have restricted knee flexion in prone. When the knees are actively flexed, the hips abduct and the hips flex. Passive flexion causes discomfort and leads to anterior pelvic tilt. 

W 2y 6m prone knee bend.jpg


References 

Mudge AJ, Bau KV, Purcell LN, Wu JC, Axt MW, Selber P, Burns J. Normative reference values for lower limb joint range, bone torsion, and alignment in children aged 4-16 years. J Pediatr Orthop B. 2014 Jan;23(1):15-25
 

Sekulić S, Zarkov M, Slankamenac P, Bozić K, Vejnović T, Novakov-Mikić A. Decreased expression of the righting reflex and locomotor movements in breech-presenting newborns in the first days of life. Early Hum Dev. 2009 Apr;85(4):263-6.

Jayakrishnan, T. T., Sharma, S., Gulati, S., Pandey, R. M., Wadhwa, S., & Paul, V. K. (2013). Agreement between visual and goniometric assessments of adductor and popliteal angles in infants. Journal of Pediatric Neurosciences, 8(2), 93–96. http://doi.org/10.4103/1817-1745.117834

Measurement of politeal angle in the newborn https://embryology.med.unsw.edu.au/embryology/index.php/Neural_Exam_-_Ne...