Study Level of evidence Group ( , sex, mean age) Type of surgery; time from injury/surgery Equipment, outcomes Task Results Effect size, Cohen’s Baumeister et al. [47 ] Case-control, 3b ACLR ( , 7M, 2F, ) Healthy ( , 7M, 2F, ) All hamstrings; months from surgery EEG, power spectral analysis Knee extension force reproduction (50% of MVIC) Significantly higher frontal theta power in ACLR ACLR vs. healthy, - 1.33 Ochi et al. [45 ] Case-control, 3b ACLD ( , 2M, 24F, ) ACLR ( , 21M, 21F, ) Normal ACL ( , 7M, 12F, ) All hamstrings; >13 months after surgery in 38 ACLR participants EEG—SEP of the ACL Direct mechanical stimulation of the ACL during arthroscopy (under general anaesthesia) Mechanically reproduced SEPs were observed in 58% of ACLD, 86% of ACLR, and 100% of healthy ACL No differences in SEP mean voltage between the ACLD (1.3 μ V), ACLR (1.27 μ V), and normal ACL (1.42 μ V) ACLD vs. ACLR, ACLD vs. healthy, ACLR vs. healthy, d = 0.30 Ochi et al. [46 ] Case-control, 3b ACLD ( , 16M, 16F, ) ACLR ( , 13M, 10F, ) Normal ACL ( , 9M, 5F, ) Hamstring graft in 22 patients and 1 allogeneic fascia lata graft; >18 months after surgery EEG—SEP of the ACL Electrical stimulation of the ACL during arthroscopy (under general anaesthesia) Reproducible SEPs in 47% of ACLD, 96% of ACLR, and 100% of healthy ACL The mean SEP voltage of the ACLD (0.74 μ V) was significantly lower ( ) than the healthy group. No differences between ACLD and ACLR ACLD vs. ACLR, ACLD vs. healthy, ACLR vs. healthy, Miao et al. [56 ] Case-control, 3b ACLD ( , all males, ) Healthy ( , all males, ) months since injuryEEG, power spectral analysis EEG was recording during the following: (1) Walking (20 m at a natural speed) (2) Jogging (20m) (3) Landing task (25 cm height) The ACLD group showed a significant increase in band power of all frequencies, during all tasks ACLD vs. healthy Walking, - 4.07 Jogging, - 3.76 Landing, - 4.46 Valeriani et al. [42 ] Case-control, 3b ACLD ( , no information on sex of patients, ) Healthy ( , 9M, 11F, ) Between 12 and 96 months after injury EEG—SEP of the common peroneal nerve and posterior tibial nerve Patients relaxed in supine Seven subjects from the ACLD group showed SEP abnormalities (loss of P27) after common peroneal nerve stimulation Unable to determine Valeriana et al. [43 ]. Case-series, 4 ACLR ( , sex and age unknown) All patellar tendon; time from surgery/injury unknown EEG—SEP of the common peroneal nerve Patients relaxed in supine Absence of cortical P27 response in the injured limb before, and after, ACL reconstruction surgery Unable to determine Baumeister et al. [29 ] Case-control, 3b ACLR ( , 7M, 3F, ) Healthy ( , 9M, 3F, ) All hamstrings; months from surgery EEG, power spectral analysis Reproduce a given knee angle of 40° Significantly higher theta and alpha 2 power in ACLR Unable to determine Courtney et al. [34 ] Case-control, 3b 17 ACLD patients (7M, 10F), divided in the following: noncopers ( , ), adapters ( , ), and copers ( , ) Overall after injury: noncopers: 90 months, adapters: 59 months, and copers: 69 months EEG—SEP of the common peroneal nerve Patients relaxed in supine The adapter group showed normal SEPs, 75% of noncopers had normal SEPs, and all copers had altered SEPs Unable to determine Courtney et al. [57 ] Case-control, 3b 15 ACLD patients (5M, 10F, ), divided in the following: noncopers ( ), adapters ( ), and copers ( ) Overall mean = 67 months after injury: noncopers: 85 months, adapters: 63 months, and copers: 69 months EEG—SEP of the common peroneal nerve Patients relaxed in supine The adapter group showed normal SEPs, 75% of noncopers had normal SEPs, and all copers had altered SEPs Unable to determine Lavender et al. [41 ] Case-control, 3b 11 patients: 4 with intact ACL, 6 with complete rupture, and 1 with partial rupture. No information on sex and age 28 months ( - 96) after injury EEG—SEP of the ACL Electrical stimulation of the ACL during arthroscopy All intact ACLs (and the partially ruptured) showed reproducible SEPs; ruptured ACL did not show reproducible SEPs Unable to determine Kapreli et al. [23 ] Case-control, 3b ACLD ( , all male, ) Healthy ( , all male, ) months after injuryfMRI Cycles of 45° knee extension/flexion (1.2 Hz), during 25 s, positioned in supine inside the scanner ACLD showed less activation of thalamus, PP, PM, cerebellum, iSM1, cSM1, BG GPe, and CMA and showed higher activation of pre-SMA, SIIp, and pITG Unable to determine Grooms et al. 2017 [49 ] Case-control, 3b ACLR ( , 7M, 8F, ) Healthy ( , 7M, 8F, ) 13 hamstrings and 2 patellar tendons; months after surgery fMRI s cycles of 45° knee extension/flexion (1.2 Hz), positioned in supine inside the MRI scannerACLR showed less activation of iMC and cerebellum and showed higher activation of cMC, lingual gyrus, and iSII for the following: , , , lingual , and