Strength Isometric Test: Prone Hip External Rotation

Here is a general overview of the testing protocol for prone hip external rotation (ER) isometric strength:

1. Have the client adopt a prone position on a massage table, with the testing leg flexed at the knee to 90 degrees.
2. It is recommended that the practitioner set themselves up on the contralateral side of the massage table to conduct this test.
3. The practitioner should manually bring the client’s leg into roughly 5 degrees of hip internal rotation, then using the Muscle Meter, place it just above the client’s medial malleolus. 
4. Fix the client’s femur on the table to prevent unnecessary hip abduction, before queuing them to externally rotate, pressing against the Muscle Meter as best they can for 2-3 seconds until peak force is achieved.
5. Upon completion, hit save on the Measurz app and compare to the opposite side.

Normative data for hip external rotation isometric strength with a muscle meter can vary depending on several factors, including age, sex, and functional level. Additionally, different studies may use different units of measurement, such as torque or force.

Here are a few examples of normative data reported in the literature:

• One study of healthy young adults aged 18-30 years reported average peak torque values of 23.2 Nm (±6.7) for males and 13.7 Nm (±4.1) for females (Katz-Leurer et al., 2009).
• Another study of healthy young adults aged 20-30 years reported peak force values of 17.9 kgf (±3.3) for males and 11.8 kgf (±2.1) for females (Kawczynski et al., 2020).
• A study of healthy older adults aged 65-89 years reported peak torque values of 7.7 Nm (±3.6) for males and 4.6 Nm (±2.2) for females (Molloy et al., 2010).

References:

1. Katz-Leurer, M., Rotem, H., Keren, O., & Meyer, S. (2009). Hand-held dynamometry in patients with hip fracture: reliability and validity of measurements of muscle strength. Journal of Rehabilitation Medicine, 41(7), 572-576.
2. Kawczynski, A., Stastny, P., Petr, M., & Mostowik, A. (2020). Inter-rater reliability and measurement error of isometric hip strength measurements using a hand-held dynamometer. Journal of Human Kinetics, 73(1), 55-62.
3. Molloy, D. W., Richardson, J. K., Crilly, R. G., & MacIntyre, D. L. (2010). A comparison of isometric, isotonic concentric and isotonic eccentric hip abductor and external rotator torque in healthy older adults. Archives of Gerontology and Geriatrics, 51(3), e90-e93.