I have osteoarthritis through my left hip, which has eroded the joint to the extent that my only real option is to have a hip replacement (September, YES!)
While I used to run endurance-style (racking up 16 - 20km daily) as a teenager, thankfully I stopped that and turned to weight-training in my early 20s. Consistently training with challenging weights, ensuring proper technique and balancing front/back, pushing and pulling, upper and lower body has resulted in NO muscle wastage. According to my surgeon, this is extremely rare in cases of osteoarthritis and he has recommended I stick with my weight-training and low-impact cardio training. My left leg and hip are particularly vulnerable to post-training tightness and soreness that can keep me up in the middle of the night sometimes, but I have an arsenal of tools for when this happens. They are also great for back and neck tension/soreness, calf and plantar fascitis pain.
I massage my upper back and neck by placing the bakball against a wall and pressing into it with my body weight. By squatting down and keeping my back close to the wall, I can manipulate the tool to run up and down my spine. I use the softer red version. If I need to target right into a sore spot, I use a knobbly massage ball. I bought mine from a trainer at the gym for $10 (thanks Aaron!) but they are available through physios and online.
Lying prone and extended on the foam roller, I use my arms to help me to roll forwards and back, pressing my quadricep (upper, front thigh) into the foam roller from the front and outer angles. I also make sure to target the iliolotal band (fibres that run from hip to knee) because it tightens and pulls on both the hip and knee, causing an achy soreness that can easily be "rolled" out!
Mentholatum Ice Gel is available in supermarkets for under $5. It is insanely good. I apply it to the back of my neck and shoulders as well as to my hip and just above my knee. I also just had a nasty 48-hour killer sore throat and swollen glands. Ice gel applied around the glands in my neck gave me major relief! Considering cost per use, this is a MUST HAVE.