Nature has designed the male and female bodies regarding their function. It’s all about reproduction. 

Females have a wider pelvis, adapted for childbearing !

One of the most obvious difference between male & female skeletons is their pelvis and their legs. 

What is the Q-Angle ? 

The wider hips and angled femurs make it harder to controll the knees, especially with dynamic movements like jumping, hopping, skipping and running. 
That's why women are more prone to knee injuries than men. 

Women with very large hips tend to have knee valgus, which is when the knees collapse inwards.

Women's knees have to rotate when walking, while men's knees do not rotate.

The differences are mechanical, physiological. That's why men and women walk differently.

The Female Hipline

The widest part of a female body is where the Femurs join the hips. The two hipbones form the part of the pelvis called the pelvic girdle.
The hips are usually as wide as or wider than the shoulders. 

The Female Gait 

Female Skeletons have wide hips, so their Femurs are angled. The angled Femur renders the Female Gait like that of a Runway Model (catwalk). Although all of the Runway Models are Males mimicking the Female walk.

When the Female Skeleton is walking, the wide Female pelvis causes the leg to swing outward, the knees separate during her stride. Female legs cross each other when walking.

Female knees separate when walking, which produces the Female Triangle when the knees are at a height.

This is why there is no space between where the feet fall. Females swing their foot from back to front in line position.

The Male Gait 

The Male Skeleton has narrow hips, so their Femurs are straight. The straight femur renders the Male Gait similar to that of a toy soldier. 
Males kick their legs straight forward when they walk. This leaves a space between where the feet fall.

Men's knees stay together during the stride. Male femurs are straight and male knees do not rotate.

watch more examples of gaits

The Catwalk Mimick Gait

Males mimicking the Female gait put their feet in line, but they keep their knees together. 

If these were FEMALE skeletons walking, the ones with the arrow above their heads should display the FEMALE TRIANGLE at this exact moment.

Straight femurs and a narrow pelvis = biological Male

All of the „female“ models are biological males. Since ever. Prepubescent boys on Estrogene. Lookalike women.
All of them have a special posture to hide the real width of their shoulders.

Descending stairs

Try this for yourself.

You are a male, try walking like women. You'll have a hard time keeping balance, unless you are trained to walk this way. 

You are a female, try walking like a tin soldier. You'll get pain in your hip joints.

And you will have to remember to walk lilke the opposite gender. It's not that easy, without constant exercise.

This is what it looks like when a biological Female walks with her knees together: the lower legs stick out !

train your brain : examples of gaits