Starting at the top, let's examine the leg pressure points.
Highest, of course, is the groin. Known to almost anyone, this area
is by far the most sensitive nerve center. This is usually anticipated
by attackers and subsequently is protected.
If you are in close a knee strike would be effective. I would not
move in close to perform this technique. If you are a little farther
out a front snap kick would work well, if you were fast enough to execute this without his grabbing your foot or ankle first.
I would not recommend grabbing an squeezing the testicles, as taught by some groups. Remember the object is to get away as soon as possible!
Pinching inner thigh while being held
The inner thigh is another one of the leg pressure points. This is not an area that I would use for a kick or hand strike, though. If I were grabbed from behind over my arms, which are at my sides (apparently I didn't see this coming) I would shift my hips to one side and back. This would bring one of my hands to this location and I would then pinch the inner thigh as hard as I could. This would cause sufficient intense pain to make my attacker let go of me so I could run.
The knee is an ideal self defense target. It is vulnerable from every angle. It is within reach of smaller defenders, such as women. It can be kicked without risk of the foot being grabbed. Injuries caused by attacking the knee are usually not life threatening.
Side kick to the front of the knee
Kicking the back of the knee will most likely only cause the attacker to fall, while kicking to the side could also cause some injury, partially incapacitating them. Kicking the front of the knee is less likely to unbalance, but more likely to cause injury to the knee cap or ligaments.
Snap kick to back of knee
This is a very sensitive nerve center, as most of you know from bumping into coffee tables and other hard furniture. A kick to this region would cause excessive pain, proving to be an effective leg pressure point.
If someone were to grab you from behind I would recommend raising one of your feet up to the attacker's knee, slam your heel against the top of their shin and scrapping your heel against their shin as you press as hard as you can, finishing with a stomp to the top of their foot. This technique is best if wearing shoes, but worth using even if you are not.
If the assailant is in front of you a kick to the shin is also
effective. This method is effective no matter the size of the attacker.
While the ankle is susceptible to pain, it is also vulnerable to sprain. A stomping kick to the side of the ankle would cause pain and could possibly result in sprain, fracture or both.
Here we have three main targets, the back of the thigh, the back of the calf and the Achilles Tendon. Any of these would make an excellent kicking target. It would cause great pain and possibly cause a buckling of the knee to bring your attacker down. Muscle spasms could be the result of a blow to the back of the thigh or calf.
The Achilles Tendon is the long ligament that runs from the calf muscle to the heel. It can be susceptible to tearing injury. An assault of the Achilles Tendon would best done with a kick with the side of the foot or the toe of a shod foot.
The instep is the top part of the foot between the toes and ankle. Because there are many small bones in the foot, stomping here could cause a a disabling fracture. I would recommend a side kick to the shin, scraping down the shin bone and stomping on the instep. This should buy you enough time to escape.
There are many leg pressure points, it just depends on what is
available when you are attacked. Their use can be an effective part of a
women's self defense plan.