Ultrasound imaging is widely used to measure architectural features of human skeletal muscles in vivo. We systematically reviewed studies of the reliability and validity of two-dimensional ultrasound measurement of muscle fascicle lengths or pennation angles in human skeletal muscles. A comprehensive search was conducted in June 2011. Thirty-six reliability studies and six validity studies met the inclusion criteria. Data from these studies indicate that ultrasound measurements of muscle fascicle lengths are reliable across a broad range of experimental conditions [intraclass correlation coefficient (ICC) and r values were always > 0.6, and coefficient of variation values were always < 10%]. The reliability of measurements of pennation angles is broadly similar (ICC and r values were always > 0.5 and coefficient of variation values were always < 14%). Data on validity are less extensive and probably less robust, but suggest that measurement of fascicle lengths and pennation angles are accurate (ICC > 0.7) under certain conditions, such as when large limb muscles are imaged in a relaxed state and the limb or joint remains stationary. Future studies on validity should consider ways to test for the validity of two-dimensional ultrasound imaging in contracted or moving muscles and the best method of probe alignment.

What is the incidence of recovery of ambulation and upper limb function six months after stroke? Can measures such as age and the National Institutes of Health Stroke Scale (NIHSS) be used to develop models to predict the recovery of ambulation and upper limb function? Prospective cohort study. Consecutive sample of 200 people with stroke admitted to a Sydney Hospital. Ambulation was measured with item 5 of the Motor Assessment Scale (MAS); patients scoring ≥3 could ambulate independently. Upper limb function was measured with items 7 and 8 of the MAS; patients scoring ≥5 could move a cup across the table and feed themselves with a spoonful of liquid with the hemiplegic arm. Of the 114 stroke survivors who were unable to ambulate initially, 80 (70%) achieved independent ambulation at six months. Of the 51 stroke survivors who could not move a cup across the table initially, 21 (41%) achieved the upper limb task at six months. Of the 56 stroke survivors who were unable to feed themselves initially, 25 (45%) could feed themselves at six months. Models containing age and severity of stroke (measured with NIHSS) predicted recovery of ambulation and ability to move a cup across the table, whilst a model containing severity of stroke predicted ability to feed oneself. All prediction models showed good discrimination (AUC 0.73 to 0.84). More than two-thirds of people after stroke recovered independent ambulation and less than half recovered upper limb function at six months. Models using age and NIHSS can predict independent ambulation and upper limb function but these prediction models now require external validation before use in clinical practice.

What is the incidence of contractures six months after stroke? Can factors measured within four weeks of stroke predict the development of elbow, wrist, and ankle contractures six months later? Prospective cohort study. Consecutive sample of 200 adults with stroke admitted to a Sydney hospital. Loss of range of motion in major joints of the body was measured using a 4-point ordinal contracture scale. In addition, elbow extension, wrist extension, and ankle dorsiflexion range of motion were measured using torque-controlled procedures. Potential predictors of contracture were age, pre-morbid function, severity of stroke, muscle strength, spasticity, motor function, and pain. Measurements were obtained within four weeks of stroke and at six months after stroke. 52% of participants developed at least one contracture. Incidence of contracture varied across joints from 12% to 28%; shoulders and hips were most commonly affected. Muscle strength was a significant predictor of elbow, wrist, and ankle joint range. Prediction models explained only 6% to 20% of variance in elbow, wrist, and ankle joint range. About half of all patients with stroke develop at least one contracture within six months of stroke. Incidence of contractures across all joints ranged from 12% to 28%. Muscle strength is a significant predictor of elbow, wrist, and ankle contractures but cannot be used to accurately predict contractures in these joints.