My Husband Has Hurt His Right Knee And Is Unable

My husband has hurt his right knee and is unable to walk without a support. His knee is swollen on the inside and back. It is painful for him to bend his knee. We are not sure what he did to injure it but 2 days ago he did do about a minute or two of alternating deep knee bends and toe touches. The pain started much later yesterday he remained in bed with his leg elevated. Getting up was very painful and he needs a support to get to the bathroom. The swelling became very obvious today. We are using ice and elevating the leg. We are not currently in a location near our family doctor so would like advice as to how to proceed with care.