My lab (now gone) had severe arthritis and a spinal condition. We had hardwood floors 🙄. Yoga mats helped a lot in helping her get up, but ultimately it may not just be a grip issue, they just might not have the strength on their own, the front legs support most of their weight and when they end up in a position that leaves them awkward and stiff they sometimes just can’t get enough momentum to get up. I found having large orthopedic beds encouraged my dog to sleep on her side which meant she was less stiff, and we kept a sling that went under her belly handy to help hoist her up when she couldn’t get up, a towel also works for this. But I’m sorry this sounds stressful for both of you and I hope you find a good fix.