Types of running styles:
run using our legs but some people use just a fraction of their power.
When runners move from their hip joints and keep a relatively straight leg, minimally bending at the knees.
Some of us hold the thighs together whilst moving mainly from the knees.
A lot of runners run with 'knock knees' landing on dropped foot arches. Sometimes only one knee is 'knocking. This can be due to one leg being longer than the other.
Leg length differences:
Most of us have one leg longer than the other. From years of analysing postural X rays I noted that an average leg length difference of 1 centimetre is normal. If the difference is more than 2 centimetres the skeletal compensations cannot cope very well. The picture below shows the pelvic distortion at the sacro-iliac joints due to excessive leg length discrepancy.
This habit affects the IT band (also named as the Iliotibial tract, Tensor fascia latae and TFL).
With every stride and step we take the TFL plays the important role of stabilising the leg as it passes through the midline of the stride. The harder we slam our foot down or throw our leg out to the side the more the TFL tenses up. This muscle will also be hypertoned if the spine is habitually leaning to one side. If we lean to the left then the right TFL will tense up and vice-versa. This little muscle is very prone to a deep hypertonic state. In this state it will pull on the IT band causing pain, misalignment and can even spread into the buttock muscles and contribute to Sciatic nerve irritation.
Uneven stride length:
We often will have one leg which has a longer stride. This is usually the dominant leg. One can observe this on video and by the sound or rhythm of our footfall being unequal. It is most optimal to have equal stride lengths.
This type of running can be due to the knock-kneed type. The feet flare out with every step.
They have their heads poked forwards, shoulders immobile and tensed up, elbows bent into a position where it looks like they are serving a tray of tea.