Supervision is critical to exercise safely and avoid overtaxing involved muscle groups.
Depending on your area of involvement, use strength training to help you retain and develop strength in your knee extensors, hip extensors and lower back.
Train at a sub-maximal level and focus on endurance rather than increasing your load.
Use light weights or no resistance. Begin with one set of five to 10 repetitions, and work up to three sets of eight to 12 repetitions, three sessions per week.
Two to three maximal contractions at 20-degree/40-degree/60-degree angles of involved joints.
Do not strength-train the same muscle groups on consecutive days.