The study aims to find validity and intra-inter examiner reliability of the Lever Laser Lunge Test (LLLT). This is a new way to measure ankle range of motion during weight bearing, instead of classical dorsiflexion lunge test The study wants to assume that LLLT is comparable to the traditional test but more efficient because it could be used in different settings.

To reach this goal, these two non-invasive tests will be performed to measure the amount of movement of the ankle joint in healthy teenage basketball players.

Data will be statistically compared and studied.

The dorsiflexion lunge test or knee-to-wall test (DLT) measure the range of movement of weight bearing ankle dorsiflexion. This test is frequently used in sport setting, in order to identify ankle limitations which could lead to possible injuries or joint overloads.

DLT is a cheap and simple measurement method to assess the ankle dorsiflexion, however clinicians find possible bias that reduce the usability of this test.

In order to remove this bias, this study suggests a new measurement method carried out by a level laser to create a virtual wall (the vertical red line produced by the laser).

The study aims therefore to estimate the validity and intra-inter examiner reliability of this method, in comparison to the DLT.

The instruments used are a professional level laser and a rigid ruler. A group of male teenager basketball players from Bologna competitive sports clubs will be recruited.

In order to assess the validity of this new test the clinicians will compare statistically the outcome of both test In order to assess the intra and inter examiner reliability the clinicians will compare repeated measurements of the LLLT.

It is assumed that both measurement methods (traditional and laser method) have comparable validity but LLLT reliability intra and inter examiner should be higher than the DLT one.

Inclusion Criteria:

• male teenagers basketball players enrolled in a competitive sports club;
• teenagers whose parents have signed the privacy and consent forms.

Exclusion Criteria:

• athletes who have suffered in the last 3 months of lower limb musculoskeletal disorders such as pain for more than 7 days (ankle distortion outcomes, leg/foot fractures, plantar heel pain, metatarsalgias, etc);
• athletes who have undergone surgery on their lower limb.

Male teenagers basketball players from Bologna competitive sports clubs.

IPD will be sharing by a publication and will be stored and shared with those who request it while maintaining the anonymity of participants.