Klyne DM, et al. - Researchers investigated if generalized hyperalgesia and impaired pain modulation are present in the acute-phase of low back pain (LBP). For this, they searched for differences in pain presentation in early-acute LBP and evaluated the potential contribution of other factors to variation in sensitivity. They observed enhanced sensitivity consistent with generalized hyperalgesia in early-acute LBP. Acute back pain includes four subgroups with sensitivity and modulation profiles: “high sensitivity”, “low conditioned pain modulation (CPM) efficacy”, “high sensitivity/low CM efficacy”, and “low sensitivity/high CPM efficacy”. Various factors such as sleep and alcohol explain some variation in presentation.