TY - JOUR AU - Herbert Rob AU - Hancock M. AU - Maher C. BT - Physical Therapy CN - Y LA - eng LB - MS M1 - 7 PY - 2009 SP - 698 EP - 704. ST - Phys Ther T2 - Physical Therapy TI - Clinical guide to interpretation of studies investigating subgroups of responders to physiotherapy interventions VL - 89 ER -