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For the hamstring graft ACLR, the importance of functional restoration of hamstring strength is paramount to a successful recovery. As outlined in previous blogs, the hamstrings play an important eccentric and yielding isometric role in providing a posterior translation moment on the knee during deceleration tasks.
Developing a targeted and reliable battery of testing for the function of the hamstrings is fundamental to not only guiding rehab phase progression but also in dictating the direction of program interventions, particularly in specific ranges of motion that the hamstrings may display weakness. The other finer intricacy is the timing of assessments, particularly given that the initial healing of the donor site remains a high priority.
To break down my approach to assessment of hamstring strength I utilise the following assessments at each phase:
Protection Phase -
ForceDecks Isometric 90 Deg Iso Push
Load Introduction Phase -
SL Hamstring Bridge Capacity Testing
NordBord Isometric 0 Deg Test
NordBord Isometric 30 Deg Test
NordBord Isometric 90 Deg Test
ForceDecks Isometric 90 Deg Iso Push
Strength Accumulation Phase -
NordBord Isometric 0 Deg Test
NordBord Isometric 30 Deg Test
NordBord Isometric 90 Deg Test
NordBord Nordic Fall Test
ForceDecks Isometric 90 Deg Iso Push
Training Integration Phase -
NordBord Isometric 0 Deg Test
NordBord Isometric 30 Deg Test
NordBord Isometric 90 Deg Test
NordBord Nordic Fall Test
ForceDecks Isometric 90 Deg Iso Push
Isokinetic Dynamometry Testing
Example Set Ups:
NordBord Testing
NordBord Isometric 0 Deg Test
NordBord Isometric 30 Deg Test
NordBord Isometric 90 Deg Test
NordBord Nordic Fall
ForceDecks Testing
ForceDecks Isometric 90 Deg Iso Push
Bodyweight Capacity Testing
Single Leg Hamstring Bridge Capacity Test
*Note - This test would be performed with a metronome at 60BPM with each phase (concentric & eccentric) to be performed as the beat occurs
Example Results
Below are two examples of Nordic Fall Test results, with my following interpretations...
Test 1 - This athlete displays rapid RFD in the display of a quick spike to peak torque as well as high symmetry between right and left limbs as both the orange (right leg) and blue (left leg) traces produce almost identical curves. This athlete was managed conservatively through their ACL rehabilitation via the Cross Bracing Protocol and developed an anatomical full thickness heal with a minor sag.
Test 2 - This athlete shows large discrepancies in both peak torque and RFD displayed through the journeys of the force trace on the left and right leg respectively. Whilst both display similar strategies to reach peak torque the left leg has a delayed initial response to loading and cannot produce the same levels of peak torque as the right leg. This athlete has a history of a hamstring graft ACLr
Test 3 - Self example utilising the Forcedecks for a 90 deg iso push in a supine position. Image displays the force trace from each test. Bodyweight was measured by resting heel passively on the forcedecks
Test 3 - Example sample data pulled from VALD Hub from the ForceDecks 90 Deg Supine Iso Push. Noting advantages with this test is that it displays rate of force development (RFD) with N at 100, 150 and 200ms displayed as well as time to peak force. This can have strong implications for a hamstring graft where as mentioned in previous blogs, RFD is a key deficit that persists long standing post reconstructive surgery.
Summary
Having a systemised testing approach is pivotal in ensuring optimal outcomes in sports rehabilitation. Utilising a battery of tests, primarily supported by objective data can give a clinician a strong insight into the functional recovery of the hamstrings post ACLR. My system involves the utilisation of the NordBord, ForceDecks and capacity based testing to deliver information on max torque, RFD and endurance which aids my decision making in clinical progression through rehab and return to sport.
Happy testing!