Tackles to the legs can result in bruising or bleeding to the thigh (quadriceps). These can range from a minor “dead leg”, where the player feels he can continue after some minor on field treatment, right up to being unable to continue.
Like any muscle injury, the first aid management would include DR ABC, a plastic bag of half ice/half water applied for 20 minutes every two hours and a light strapping or compression applied.
If the athlete can still walk, it is acceptable to seek a medical or physiotherapy review over the next few days if they fail to improve. If they cannot walk, however, then review by a doctor on the same day as the injury would be important. Similar treatment is acceptable for calf or hamstring strains or general soft tissue bruising.