When you tweak your back, is it better to lie down and rest?

Short answer

No. People told to rest in bed had a bit more pain and recovered more slowly, while those who kept up normal activity within their pain limits recovered fastest. Cutting bed rest from 7 days to 2 made no difference to the outcome.

When you tweak your back, is it better to lie down and rest?
'Tweak your back → stay flat in bed → heal faster' — does this formula hold?
A common belief: if you tweak your back, you have to stay in bed for a few days to heal. We used randomized trials to check who recovered faster, people who rested in bed or people who kept moving.
Those told to rest in bed had more pain
Pooled results from 11 trials with 1,963 people
In an analysis that pooled 11 trials with 1,963 people, those advised to rest in bed had a bit more pain and a bit slower recovery of function than those advised to stay active. A 2010 re-analysis also found that people who kept moving came out slightly ahead on pain and function.
Comparing three options, normal activity was fastest
Bed rest was slowest
186 people were split into 2 days of bed rest (67), back exercises (52), or normal activity within their pain limits (67). At 3 and 12 weeks, the normal-activity group did best on pain duration, pain intensity, back function and days off work. Bed rest gave the slowest recovery.
No reason to stay in bed longer either
7 days in bed meant 45% more missed work
203 people were told to rest in bed for 2 days or 7 days. The 2-day group missed 3.1 days of work versus 5.6 days, 45% fewer. Pain, function and other outcomes showed no difference. An analysis pooling several trials also found no difference between 2-3 days and 7 days.
Same for pain that shoots down the leg
Bed rest did not help more
For sciatica, where back pain shoots down the leg, there was no difference in pain or function between bed rest and staying active. None of these trials found a case where bed rest led to better recovery.
Sudden back pain drops a lot within 6 weeks
From 52 to 23 out of 100 by week 6
An analysis that pooled 33 groups with 11,166 people found that sudden back pain went from 52 out of 100 at the start to 23 at 6 weeks, 12 at 26 weeks and 6 at 1 year. It fell by more than half in the first 6 weeks, then kept falling slowly.
After recovery, walking delayed the next episode
From 112 days to 208 days
701 people who had just recovered from back pain were split into a 6-month walking program or no program. The time until the next episode was 208 days with walking and 112 days without, and the risk of a new episode was 28% lower. When it came back, recovery took 3 days versus 4, a day faster with walking.
Bottom line: moving beat bed rest
Carry on as normal, as far as the pain allows
People told to rest in bed had more pain and recovered later, and 7 days in bed did no better than 2. Sudden back pain fell by more than half within 6 weeks. Moving as normally as the pain allows, and keeping up walking once you recover, is enough.