title: Electromechanical delay of the knee flexor muscles after anterior cruciate ligament reconstruction using semitendinosus tendon.
abstract: The purpose of the study was to evaluate whether using only the semitendinosus as a tripled short graft would affect the electromechanical delay (EMD) of the knee flexors. EMD was evaluated in volunteers (N = 15) after they had undergone surgery for anterior cruciate ligament (ACL) reconstruction where the semitendinosus tendon alone was used as a graft. The results were compared with the intact leg and healthy controls (N = 15). After warming up, each subject performed four maximally explosive isometric contractions on an isokinetic dynamometer. Torques were measured by the dynamometer, while the electrical activity of the semitendinosus and biceps femoris muscles was detected using surface electromyography. EMD was found to be significantly increased (p = 0.001) in patients who had undergone ACL reconstruction compared to the controls. On the contrary, no significant differences (p = 0.235) were found for the biceps femoris muscle between the two groups. Similar results were found when the study group was compared with the intact leg group (p = 0.027 for semitendinosus and p = 0.859 for biceps femoris). Harvesting the semitendinosus tendon increases the EMD for the semitendinosus muscle but does not influence the EMD outcomes for the biceps femoris muscle.
authors.affiliation: a Biomechanics Division , The Nicola Cerulli Institute of Translational Research of the Musculoskeletal System - Let People Move Research Institute SRL , Arezzo , Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Freddolini
authors.affiliation: b International Orthopedic and Traumatologic Institute (IOTI) , Arezzo , Italy.
authors.forename: Aluena
authors.initials: A
authors.lastname: Battaglioli
authors.affiliation: b International Orthopedic and Traumatologic Institute (IOTI) , Arezzo , Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Chiechi
authors.affiliation: c Institute and Traumatology, Catholic University, Agostino Gemelli Hospital , Rome , Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Placella
authors.affiliation: d Orthopaedic Sports Medicine Center of Ioannina, Department of Orthopaedic Surgery , University of Ioannina , Ioannina , Greece.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Georgoulis
authors.affiliation: c Institute and Traumatology, Catholic University, Agostino Gemelli Hospital , Rome , Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Cerulli
authors.affiliation: a Biomechanics Division , The Nicola Cerulli Institute of Translational Research of the Musculoskeletal System - Let People Move Research Institute SRL , Arezzo , Italy.
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Gervasi
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects*; D016022:Case-Control Studies; D004576:Electromyography; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D013710:Tendons / Q000637:transplantation*; D055815:Young Adult
keywords: ACL; electromyography; hamstring; isometric contractions