Outcome measures
disability, Pain, pain
SECONDARY, CONTRACTION
The primary outcomes were pain intensity and disability, and the secondary outcomes were mobility, muscle strength, lumbopelvic stability, and LM muscle thickness. The measurement of secondary outcomes and evaluation of exercise intervention were performed by the first author (AH Huang), and the primary outcomes were evaluated by a physiotherapist with 5 years of working experience, who was blinded to the grouping of the participants.Pain intensity was assessed using the Numerical Pain Rating Scale (NPRS). The NPRS is an 11-point scale from 0 to 10, with 0 indicating “pain free” and 10 indicating “the worst painThe Timed Up and Go Test (TUGT) was used to assess the patients’ mobility. This test starts with the patient seated on a chair. At the start signal, the patient is instructed to stand up and walk as fast as possible for 3 m, turn, walk back to the chair, and return to the seated position. The time was recorded by a handheld stopwatch. Two trials were performed, and the best recorded time was used for analysisThe isometric muscle strength of the trunk extensors and flexors was measured in the sitting position using a hand-held dynamometer (MicroFET2; HOGGAN, Atlanta, GA, USA)Hip movement range was used to indicate the level of control of the lumbopelvic stability during the one-leg loading test in the supine positionRehabilitation ultrasound image measurement of the LM muscle thickness was conducted using a Philips HD11 XE ultrasound imaging apparatus with a 5–12-MHz linear transducer (Philips Medical Systems, Bothell, WA, USA). The participants were positioned in prone, with a pillow placed under the lower abdominals to minimize lumbar lordosisTo determine the relative variation of individual muscle thickness, the thickness value obtained in each contraction task was subtracted from the value obtained when the LM muscle was in the resting position and then divided by the value in the resting position.