Introducing three new additions to our testing and training repertoire that have been designed to assist with the assessment and training of unilateral adductor isometric strength through the hip abduction range.
With the athlete in a side-lying position and externally stabilised at the hips with a belt or the manual downward pressure from a practitioner, we are able to assess maximal isometric adduction in neutral, 30° and 45° of abduction. The ability to assess a muscle group in a lengthened position has been shown to provide interesting findings following muscle injury in other areas. Nara et al (2022) found deficits in isometric peak muscle strength of limbs with a history of hamstring muscle injury at the lengthened muscle position, but not in the unstretched position. The utilisation of the 30° and 45° unilateral adduction protocols in conjunction with existing bilateral adduction protocols may provide valuable insight into an athlete's risk profile following an adductor muscle injury.
The influences of training in lengthened vs shortened positions have also been documented. Kubo et al (2005) assessed muscle size and function at the muscle-tendon complex following a training program at different joint angles. Knee extension was trained at 50° (short muscle length) and 100° (long muscle length) with a set of isometrics (70% MVIC 15s x6) over a 12-week period. Findings suggest that training in a long muscle length position may increase tendon stiffness and increase peak force output throughout the range vs the short muscle length.
With these protocols, practitioners have the ability to assess baseline maximal isometric strength, continually monitor athletes to identify potential risk factors and develop strength capacity using objective data to guide progression.
These protocols can now be found on KT360 and the KT User Guide.
Nara G, Samukawa M, Oba K, Koshino Y, Ishida T, Kasahara S, et al. The deficits of isometric knee flexor strength in lengthened hamstring position after hamstring strain injury. Phys Ther Sport. 2022;53:91–6
Kubo K, Ohgo K, Takeishi R, et al. Effects of isometric training at different knee angles on the muscle-tendon complex in vivo. Scand J Med Sci Sports 2006; 16: 159-67