This study aims to address these limitations by directly comparing the effects of 1) exercise to increase strength of the trunk and increase flexibility of the trunk and extremities, and 2) individualized, motor skill training directed at performance of daily functional activities that are painful or limited due to the person's LBP. This study also will examine 1) the effects of a booster phase of intervention, 2) the relationship between adherence to intervention and function, and 3) the relationship between performance of functional activities and function-related outcomes. People with chronic LBP will be randomized to 1) an intervention of strength and flexibility exercise or motor skill training, and 2) a booster or no-booster intervention. Intervention will be provided in 2 phases: 1) initial phase: 6 - 1 hour sessions, once/week for 6 weeks, and 2) booster phase: # of sessions needed to regain independence in home program, beginning 6 months after the initial phase. The investigators will collect 1) measurements of pain, function, disability, and economic outcomes, 2) reports of adherence, and 3) laboratory-based measures of performance of functional activities. People will be followed for 12 months after the initial intervention phase. Three sets of hypotheses are proposed. First, the investigators hypothesize that both interventions will result in improvements in pain, function, disability, and economic outcomes, but that the motor skill training will result in more long lasting improvements than the strength and flexibility exercise. Second, the investigators hypothesize that the effect of a booster phase of intervention will 1) result in longer lasting improvement in function and better adherence than a no-booster intervention, and 2) be greater for motor skill training than for strength and flexibility exercise. Finally, the investigators hypothesize that 1) adherence to motor skill training will be more strongly related to function than will adherence to strength and flexibility exercise, and 2) performance of functional activities by people receiving motor skill training will be more strongly related to function than performance of functional activities by people receiving strength and flexibility exercise.