How To Treat Swelling And Pain Of Foot Caused Due To An Injury?

Hi there ! I work in a care home where we use portable mechanical lifts. My partner rammed the machine into the inside of my right foot. There was no bruising But I have been getting a cramp-like feeling in that foot. less than a week later I'm experiencing swelling and pain when walking on that foot ? I'm confused as there was no brusing. What has happened here?