EXERCISE 4: POST-TRAINING EXERCISE: THE STANDING ISOMETRIC HAMSTRING STRETCH
Perform the following stretch at the end of your training session. You should not be overly fatigued when using this stretch, so incorporate it into workout sessions that are not overly difficult. The standing isometric hamstring stretch should be performed twice a week if you don't have a hamstring problem and three times a week if you are currently rehabilitating a hamstring injury.

Begin by standing with your weight fully supported on your left leg (you may place your right hand on a wall or other support to maintain your balance). Then, place your right heel on a chair, table, or other similar support in front of you. The height of this supporting structure should be somewhere between your knee and hip; the more flexible you are, the higher the support can be. Your right knee should be extended so that your right leg is straight. With your shoulders and chest facing straight ahead (towards your extended right leg), attempt to move your navel as close to your right knee as you can - until you feel a strong (but not painful) stretch in your right hamstrings.

At this point, you are ready to begin the isometric portion of the stretch. Starting gradually, attempt to push your right heel down towards the floor by contracting your right buttock, hip, and hamstring muscles for a count of six to eight seconds. This contraction should start gradually and build to close to maximal effort by the fourth second or so. Allow your muscles to relax completely for a few seconds after the contraction, and then again attempt to move your navel a little closer to your right knee. Repeat this sequence: isometric contraction - move closer to knee - isometric contraction - move closer to knee - at least three to five times before performing the entire sequence with the other leg. Rest for a short period, and then repeat with both legs. These isometric hamstring stretches will take you no more than five to six minutes to perform.

Pull bounding
Yet another way to improve the strength and dynamic mobility of the hamstrings is to perform some exaggerated pull bounding. To do this, warm up with at least 10 minutes of relaxed jogging, and then - on a gym floor or smooth grassy surface - bound quickly for about 30 to 40 metres, emphasizing longer-than-usual - but also very quick - strides. During these exaggerated pull bounds, you should focus on both increasing the forward swing of each leg (hip flexion) and also the backward pull (hip extension) of each leg once the foot has hit the ground. By doing so, you are increasing hip (and thus hamstring) range of motion, fostering the ability of the hamstrings to withstand injury-producing forward-swing forces, and also increasing hamstring strength. Progress your exaggerated pull bounding by increasing the number of reps (start with just three to four 30- to 40-metre reps), by expanding the length of the reps (to 100 metres or so), by upgrading your speed of movement, and by then moving the venue for the pull bounds from a flat, forgiving surface to a hill of moderate steepness.
This exercise builds the shin muscle, the anterior tibialis muscle on the front side of your lower leg. If you experience shin pain when walking or running, this is the muscle group that is complaining. It flexes the foot upwards, and it complains mightily if you haven't been doing much walking or running and then try to leap into increasing your speed or distance. This exercise will develop the muscle to prevent shin pain.
* Find a step so you can stand facing away from the step, with your heels on the step and your toes hanging over the drop off.
* Hold onto a railing or chair for balance.
* Flex your toes up towards your shins as far as you can. Hold this for a second.
* Release and lower your toes.
* Repeat 8 to 10 times.
http://walking.about.com/od/exercises/a/...
tanding Anterior Tibialis Shin Stretch
I like to call this the toe drag stretch.
* Standing, you may want to use a hand on a wall or other support for balance.
* Place the foot to be stretched just behind your other foot (which remains squarely on the ground), with the toe of the stretching foot touching the ground.
* Keeping your toe firmly on the ground, pull the stretching leg forward so you feel a stretch from the top of your stretching foot through your shins. # Once you feel a good stretch, hold it for 15-30 seconds.
Repeat with the other foot.
http://walking.about.com/od/stretching/a...
For groin there is the frog. See video here. Also a description if you click show all steps.
http://www.howcast.com/videos/63-How-To-...