Execution:
- The patient stands on a 31cm high box
- The patient keeps the arms in the “stop position”, which is 45° shoulder abduction and elbow flexed to 90° in order to reduce momentum from arm swing
- The patient is instructed to jump down from the box and immediately perform a maximum vertical jump
- To minimize learning effects, 3 practice trials are allowed after which 9 consecutive drop jump trials are conducted. A 10s rest between repetitions is allowed
Positive Outcome: The examiner labels the performance as either a “low-risk” or “high-risk” landing mechanism. A low-risk landing mechanism is a landing where the patella remains in line with the first toe. In a high-risk landing, the patella moves inwards and ends up medial to the first toe,
It can be helpful to film the test performance in slow-motion, which most modern smartphone cameras support natively
|
Study |
Reliability | Sn | Sp | LR+ | LR- |
| Ekegren et al. (2009) | Intra-rater ĸ=0.75-0.85 Inter-rater ĸ=0.77-0.80 |
76-87 | 60-72 | 1.9-3.1 |
0.4-0.18 |
| Redler et al. (2016) | Intra-rater ĸ=0.55 Inter-rater ĸ=0.92 |
NA | NA | NA |
NA |
| Redler et al. (2016): high-risk cut-off |
NA | 63.03 | 82.81 | 3.67 |
0.45 |
| Redler et al. (2016): medium-risk cut-off |
NA | 95.04 | 46.07 | 1…76 |
0.11 |
