Archived Comments for:
Relationship between physical activity and stiff or painful joints in mid-aged women and older women: a 3-year prospective study
Gershom Lundberg, Crawford and Lundberg X-Ray Clinic
11 April 2007
Unless I misunderstand the structure of this research, there is no random assignment of participants to active vs inactive groups.
Therefore, it is unjustified to conclude that exercise is beneficial. It may simply be that women with arthritis pain are less active, BECAUSE they are in pain.
Cause vs effect...
11 April 2007
Unless I misunderstand the structure of this research, there is no random assignment of participants to active vs inactive groups.
Therefore, it is unjustified to conclude that exercise is beneficial. It may simply be that women with arthritis pain are less active, BECAUSE they are in pain.
Competing interests
none