My Top Read of the Month: Five Vertical Jump Metrics Provide a Comprehensive Assessment of Recovery Following Anterior Cruciate Ligament Reconstruction
Dutaillis B, Collings T, Bellinger P, Timmins RG, Williams MD, Carey DL, Bourne MN. Physical Therapy in Sport. 2026;78:101897.
Disclaimer: This blogpost is written with an idea to describe this article in a simply way: Chatgpt has been used to organising my thoughts and generate an infographic
One of the biggest challenges when using force plates in ACL rehabilitation is deciding which metrics actually matter.
Modern systems such as ForceDecks can generate hundreds of variables from a single jump test. Peak force, impulse, power, jump height, contact time, velocity, RSI, and many more are available.
The problem is that many of these metrics are measuring the same underlying physical qualities. Dutaillis and colleagues used Sparse Principal Component Analysis (SPCA) to determine which jump metrics provide unique information and which are largely redundant.
Why This Matters
As clinicians, we can obtain many outcomes, but we need to extract the meaningful meaningful information.
The Paper showed
There where five principal components explained approximately 66% of all meaningful variation in jump performance following ACL reconstruction.
The big Five
1. Force, Impulse and Power (PC1) — 51% of the Variance
This was by far the most important component. It represents the athlete’s ability to produce force against the ground and generate meaningful impulse and power. In practical terms, this is the engine of jump performance. If force production is limited, overall performance will be compromised.
Key metrics include:
- Peak Force
- Mean Force
- Impulse
- Positive Impulse
- Peak Power
2. Contraction Time (PC2) — 9%
This component reflects how long it takes to move from the start of the countermovement to take-off. It provides insight into how quickly an athlete can organize and execute the movement.
Key metrics include:
- Contraction Time
- Eccentric Duration
- Concentric Duration
3. Concentric Velocity and Jump Height (PC3) — 3%
This component captures explosiveness and the ability to project vertically. Although it explains a smaller percentage of the variance, it remains highly relevant for return-to-performance.
Key metrics include:
- Peak Concentric Velocity
- Vertical Velocity at Take-Off
- Jump Height
4. Contact Time and Countermovement Depth (PC4) — 2%
This reflects movement strategy. These variables describe how the athlete structures the jump and how efficiently they use the stretch-shortening cycle.
Key metrics include:
- Contact Time
- Countermovement Depth
5. Eccentric Peak Velocity (PC5) — 1%
This subtle but potentially important metric reflects how quickly the athlete loads the knee during the downward phase. Clinically, this may provide insight into confidence, willingness to load, and eccentric control.
Key metric:
- Eccentric Peak Velocity
Clinical interpretation
PC1 Is the Foundation Force, impulse, and power accounted for more than half of all meaningful variation. The goal is not to collect more numbers. The goal is to extract meaningful information that informs better clinical decisions.
I usually looking a asymmetries in impulses, forces and power. This should be my main core output.
Citation
Dutaillis B, Collings T, Bellinger P, Timmins RG, Williams MD, Carey DL, Bourne MN. Five vertical jump metrics provide a comprehensive assessment of recovery following anterior cruciate ligament reconstruction. Physical Therapy in Sport. 2026;78:101897. https://doi.org/10.1016/j.ptsp.2026.101897
