Your symptoms (ankle pain, tightness with tingling foot and numbness in toes) can be due to pinched nerves in the back. This can be due to;
1) Herniated/degenerated disc in back
2) Lumbar spondylosis; bone spurs in the back vertebrae pressing on the nerves.
Following investigations would be required;
1) X-ray of the lower back
2) MRI of the spine
3) Nerve conduction velocity (NCV) study
4) Electromyography (EMG)
The mainstay of the treatment is physical therapy. The other investigation to done would be estimation of blood levels of Vitamin B12. Deficiency of it also may be responsible for symptoms and will need injections of the Vitamin B12.
Prevention of the cramps is the best cure; for that following measures should be employed for the ankle cramps, which you have off and on:
1) Drink water at regular intervals, even whey you are not thirsty.
2) Drink more than what you require.
3) Drink fruit juice or a sports beverage if the working conditions are hot and one sweats a lot.
4) If cramps occur frequently, stretching exercises help. Muscle relaxant like chlorzoxazone can also help.
5) Following exercise may help you before you go to bed; Stand about 30 inches from a wall and, keeping the heels flat on the floor, lean forward and slowly move the hands up the wall to achieve a comfortable stretch.
6) A few minutes on a stationary bicycle at bedtime may also help.
7) While in bed, loose covers should be used to prevent the toes and feet from pointing, which causes calf muscles to contract and cramp easily.
8) Propping up the feet up than the rest of the body may also help.
9) During the week, swimming and water exercises are a good way to keep muscles stretched, and wearing supportive footwear is also important.
10) Eating more nuts, seeds, seafood and low-fat dairy would help.
Once a cramp starts, do the following measures so it is arrested immediately;
1) Straighten the leg, flex the foot upward toward the knee, or grab the toes and pull them toward the knee.
2) Walking or shaking the affected leg, then elevating it, may also help.
Please feel free for your follow up questions.