Comparison of the effects of an 8‑week combined intrinsic foot muscle strengthening and neuromuscular training program versus usual care on lower extremity kinetics and kinematics during single‑leg landing and running in men with anterior cruciate ligament reconstruction and functional foot pronation: a randomized controlled trial

To compare an eight week combined intrinsic foot muscle strengthening and neuromuscular training program with usual care on lower extremity kinematics and kinetics during single leg landing and running in men with unilateral anterior cruciate ligament reconstruction and functional foot pronation.

Single centre, parallel group, randomized controlled clinical trial with pre‑ and post‑testing. Forty participants will be randomly allocated 1:1 to intervention or control using computer‑generated simple randomization with concealed allocation; trial phase is not applicable.

Participants will be recruited from orthopedic and physiotherapy clinics in Hamedan. Testing is in lab and training in sports facility; assessors and analysts are blinded

Men aged 18–40 years with unilateral anterior cruciate ligament reconstruction (hamstring autograft, 12–24 months post‑surgery), at least six months standard rehabilitation, functional foot pronation, and ability to run and jump pain‑free will be included. Those with other major lower limb injuries, neurological disorders, recurrent ligament injury, or specific foot or lower limb training in the previous six months will be excluded.

The intervention group will receive an eight week supervised program, three sessions per week, including intrinsic foot muscle strengthening and neuromuscular training in addition to usual activities. The control group will continue usual care without extra structured exercise and will be offered the program after post‑intervention assessments.

Main outcomes are hip, knee and ankle joint angles and ground reaction forces and joint moments during single leg landing and running. Selected functional performance tests will be assessed as secondary outcomes.

Randomization was performed at the individual level using a computer-generated simple randomization procedure. First, a list of eligible participants was prepared. Then, an independent researcher who was not involved in participant recruitment, assessment, or intervention delivery generated the random allocation sequence in Microsoft Excel using the RAND() function. Each participant was assigned a unique code, and codes were randomly allocated in a 1:1 ratio to the intervention group (combined intrinsic foot muscle strengthening and neuromuscular training) or the control group (usual care). The random sequence was created before the start of recruitment and was transferred to a series of sequentially numbered, opaque, sealed envelopes. For each newly enrolled participant, the next envelope in numerical order was opened by a person not involved in outcome assessment, and the group assignment inside was implemented. No stratification factors were used (i.e., no stratified randomization). Allocation concealment was ensured by using the opaque sealed envelopes and by keeping the randomization list inaccessible to the investigators and outcome assessors until the moment of assignment.

In this randomized controlled trial, blinding is implemented at the level of outcome assessors and data analysts. Participants: All participants are fully informed that they are taking part in a randomized controlled trial with two different exercise programs. They provide written informed consent prior to randomization. Participants are not told which program is considered the primary experimental intervention in order to reduce expectation bias, but due to the differences in content and intensity between the exercise protocols, full participant blinding is not feasible. Care providers: The exercise trainers/physiotherapists who deliver the intervention necessarily know which exercise program they are administering to each participant. Therefore, care providers are not blinded to group allocation. Investigators: The principal investigator and co-investigators are responsible for protocol development, supervision of recruitment, and safety monitoring, and thus inevitably have access to information about the intervention protocols. Although they are not involved in the day‑to‑day outcome measurements, they cannot be considered fully blinded in all their roles. Outcome assessors: Outcome assessors who perform biomechanical and functional assessments (e.g. kinematic, kinetic, and performance measurements) are blinded to group allocation. Participants are identified only by a unique study code during assessment sessions, and assessors do not have access to the randomization list or to any information revealing group assignment. Assessment visits are scheduled and coordinated by a study coordinator who is not involved in outcome measurements, to minimize the risk of unblinding. Data analysts: Data are exported in a coded format, with intervention groups labeled as, for example, “Group A” and “Group B” without indication of which is the experimental or control condition. The statistician/data analyst performs all primary analyses using these anonymized group codes and remains blinded to the actual meaning of group labels until the main analyses are completed and the analysis plan is finalized. Data and Safety Monitoring Board: No formal Data and Safety Monitoring Board (DSMB) is established for this investigator‑initiated, small‑scale exercise trial. Safety monitoring is performed by the investigators, who are not blinded to the overall study design.

Deidentified individual participant data (IPD) and supporting study documents The following items may be shared with qualified researchers upon reasonable request: – Deidentified individual participant data (IPD) for all enrolled participants, including baseline characteristics, intervention allocation, and all outcome measures related to knee biomechanics, functional performance, pain, and patient-reported outcomes. No directly identifying variables (e.g., name, national ID, phone number, address) will be included. – The final version of the study protocol and, if applicable, the English translation of the ethics committee–approved protocol. – The template of the informed consent form used in this trial, with all identifying information removed. – The analytic code/scripts used for data processing and statistical analysis (e.g., scripts in MATLAB/Python/SPSS/R or other software used in the study). – A data dictionary describing variable names, definitions, units, coding schemes, and valid ranges for all shared variables.

Deidentified IPD and supporting documents will be made available after the main results of the trial have been published in a peer-reviewed journal. The anticipated starting time for data availability is within 6 to 12 months after publication of the primary results. Data and documents will remain available for at least 5 years after the date of first publication, or longer if required by journal or funder policies.

Deidentified IPD and supporting documents may be shared with independent researchers affiliated with academic or non-profit research institutions who have a scientifically sound proposal that is consistent with the aims of the original trial and with ethical principles. Requests from researchers working in for-profit or industry settings may also be considered on a case-by-case basis, provided that there is no conflict with participant confidentiality, institutional policies, or relevant legal/ethical requirements.

Data and documents will be shared only for non-commercial, ethically sound research purposes, such as meta-analyses, secondary analyses related to musculoskeletal biomechanics, injury prevention, rehabilitation, or other closely related research questions. The following criteria will apply: – The requesting researcher must submit a brief research proposal describing the objectives, methods, planned analyses, and data requirements. – The proposed use of data must be scientifically justified, must not overlap inappropriately with ongoing analyses by the original investigators, and must be consistent with the informed consent obtained from participants and the ethics committee approval. – The requesting institution must provide evidence of local ethics approval or waiver for the proposed secondary analysis, if applicable. – A data use agreement (DUA) must be signed, specifying the conditions for data use, data security, prohibition of re-identification attempts, prohibition of data sharing with third parties, and obligations regarding acknowledgement of the original investigators and citation of the primary publication. – Data will be shared in a secure format (e.g., encrypted files), and only deidentified variables will be included. – Any results derived from the shared data must be reported in an aggregated, non-identifiable form.

Interested researchers should send their data-sharing requests by email to the principal investigator.

The process for requesting access to deidentified IPD and supporting documents will involve the following steps: Initial contact: The interested researcher sends an email to the principal investigator briefly describing the proposed secondary analysis (research question, main methods, and data needed). Submission of documents: If the proposal is potentially acceptable, the requester will be asked to submit:– A short written proposal (2–5 pages)– A recent curriculum vitae (CV) of the responsible researcher– Evidence of local ethics committee approval or waiver (if applicable) Review of request: The principal investigator (and, if needed, the supervising committee or local ethics committee) will review the request to ensure scientific merit, feasibility, and consistency with the original consent and ethical requirements. This review is expected to take approximately 4 to 8 weeks, depending on the complexity of the request. Data use agreement: If the request is approved, a data use agreement (DUA) will be sent to the requester. Data will be shared only after both parties have signed the DUA. Data transfer: After the DUA is finalized, the deidentified dataset, data dictionary, relevant code/scripts, and agreed supporting documents will be transferred in a secure manner (e.g., encrypted files via secure file transfer or password-protected archive). The overall time from initial request to data access is expected to be approximately 1 to 3 months, depending on the completeness of the applicant’s documents and the complexity of the proposed analysis.

All data sharing will be conducted in accordance with applicable institutional policies, national regulations, and the conditions specified in the ethics committee approval.