Strength Isometric Test: Prone Hip Internal Rotation

To test prone hip internal rotation (IR) isometric strength with a Muscle Meter, you can follow these steps:

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

Some studies have reported normative data for hip internal rotation isometric strength using a muscle meter in units of force, such as Newtons or pounds. For example, one study of healthy adults aged 18-50 years found that the average peak force for hip internal rotation isometric strength was approximately 33 Newtons for men and 24 Newtons for women (Kawczynski et al., 2020). Another study of healthy young adults aged 18-30 years found that the average peak force for hip internal rotation isometric strength was approximately 49 Newtons for men and 35 Newtons for women (Katz-Leurer et al., 2009).

Other studies have reported normative data for hip internal rotation isometric strength using a muscle meter in units of torque, such as Newton-meters or pound-feet. For example, one study of healthy older adults aged 65-89 years found that the average peak torque for hip internal rotation isometric strength was approximately 10 Newton-meters for men and 7 Newton-meters for women (Molloy et al., 2010).

References:

1. Hislop HJ, Montgomery J. Daniels and Worthingham's Muscle Testing: Techniques of Manual Examination and Performance Testing, 9th ed. Philadelphia: Saunders/Elsevier, 2013.
2. Mentiplay BF, Perraton LG, Bower KJ, Adair B, Pua YH, Williams GP, et al. Assessment of lower limb muscle strength and power using hand-held and fixed dynamometry: a reliability and validity study. PLoS One. 2015;10(10):e0140822.
3. Youdas JW, Krause DA, Hollman JH, Harmsen WS, Laskowski E. Validity and reliability of strength measures from the Myotest and Jamar hand-held dynamometers in adults. J Hand Ther. 2009;22(3):266-273.
4. Bohannon RW. Hand-held compared with isokinetic dynamometry for measurement of static knee extension torque (parallel reliability of dynamometers). Clin Phys Physiol Meas. 1990;11(3):217-222.