Hello, Thanks for your query. Traumatic injury can lead to bruise due to hematoma formation. Due to blunt injury there can be hematoma collection .The bleeding that occurs result in hematoma collection. Over a period of time, as hematoma resolves it cause local skin symptoms around the hematoma. Leg and ankle swelling might be due to pooling of blood. I suggest you to consult an orthopaedician nearby for a detailed examination. You may get the X-ray of the area affected under his/her guidance.Beside icing and elevating it, you can take anti-inflammatory drug like motrin to reduce pain and inflammation. Avoid putting weight and rest well. I do hope that you have found something helpful and I will be glad to answer any further query. Take care