passive knee flexion, 27 , 28 and typically treat the patellar tendon as uniform and inextensible, assumptions which could lead to significant inaccuracies. 29 Thus, the purpose of this study was to evaluate patellar tendon motion during passive knee flexion to observe whether nonuniformity in
Laura C. Slane, Stijn Bogaerts, Darryl G. Thelen, and Lennart Scheys
Gabriel dos Santos Oliveira, João Breno de Araujo Ribeiro-Alvares, Felipe Xavier de Lima-e-Silva, Rodrigo Rodrigues, Marco Aurélio Vaz, and Bruno Manfredini Baroni
Hamstring strain injury (HSI) is one of the most common injuries in team sports. 1 Cohort studies have supported that athletes with low eccentric knee flexor strength are more prone to sustain an HSI. 2 – 6 In addition, although restoring strength is a widely used criterion for discharge from
Christopher Michael Brogden, Lewis Gough, and Adam Kelly
Nordbord allows eccentric knee flexor strength to be assessed quickly and efficiently in a more ecologically valid environment, 17 with various studies 13 , 16 identifying reduced strength when measured on the NordBord to be a risk factor for HSI. However, these studies have all been conducted in a state
Salman Nazary-Moghadam, Mahyar Salavati, Ali Esteki, Behnam Akhbari, Sohrab Keyhani, and Afsaneh Zeinalzadeh
knowledge of the authors, no study has been conducted to examine the reliability of the knee flexion–extension LyE in patients with ACLD and healthy subjects. It is well known that the reliability is a population- and condition-specific property. Therefore, it is necessary to establish the reliability of
Raki Kawama, Masamichi Okudaira, David H. Fukuda, Hirohiko Maemura, and Satoru Tanigawa
that individual hamstring muscle activity varied depending on the joint angle during isometric knee-flexion exercise. Hirose and Tsuruike 16 showed that the muscle activation of BFlh and SM increased as the knee-flexion angle was decreased, whereas that of the ST was increased according to an increase
Maria Angelika Peer and Nigel Gleeson
preventing ligamentous injury. 3 Potentially harmful dynamic forces need counteracting by synergistic patterns of muscular activation and timely neuromuscular system responses in order to protect ligamentous tissue against injury. 3 , 4 The knee flexors restrain anterior tibio-femoral displacement and
David C. Kingston and Stacey M. Acker
There is no current 3D musculoskeletal (MSK) model of the knee that can incorporate the effects of intersegmental contact during high knee flexion postures. Intersegmental contact is a critical parameter when modeling high knee flexion movements (knee flexion exceeding 120° 1 , 2 ) as its omission
Diulian Muniz Medeiros, César Marchiori, and Bruno Manfredini Baroni
factors for HSI in an attempt to contribute to the development of prevention programs. The risk factors can be divided in nonmodifiable (eg, previous injuries, age, and genetics) and modifiable (eg, flexibility, fatigue, eccentric strength, and fascicle length). 27 , 28 Knee flexors eccentric strength 29
Jacob T. Hartzell, Kyle B. Kosik, Matthew C. Hoch, and Phillip A. Gribble
history of an ankle sprain. 12 Adequate knee flexion is important for attenuating the large, potentially harmful, ground reaction forces encountered during a jump landing. Therefore, it has been suggested that less sagittal plane knee motion at initial contact is associated with the heightened risk of a
Kenny Guex, Chantal Daucourt, and Stéphane Borloz
In the field of sport rehabilitation, an easy, valid, and reliable assessment of maximal strength is crucial for efficient muscle rehabilitation. Classically, it is performed on fitness equipment that is not necessary available in the field. Thera-Band has developed elastic bands with different resistances depending on the color of the band and on the percentage of its stretch. This may allow testing maximal strength.
To determine validity and reliability of maximal-strength assessment of knee flexors and extensors using elastic bands.
Reliability and validity study.
22 healthy participants (31.3 ± 7.0 y, 175.5 ± 8.5 cm, 70.7 ± 12.9 kg).
Participants performed 2 maximal-strength assessments, separated by 7 d, of the knee flexors and extensors using elastic bands. After the 2nd trial, a maximal concentric isokinetic test at 60°/s was performed.
Main Outcome Measures:
Correlations between 1-repetition maximum using elastic bands and peak torque on an isokinetic dynamometer were used to determine the validity of the proposed method, while ICC, CV, and SEM were used to determine reliability between the 1st and 2nd trials.
The validity of the proposed method was found to be very high (r = .93 for both knee flexors and extensors). The relative reliability was found to be very high (ICC = .98 and .99 for knee flexors and extensors, respectively), while absolute reliability was also very satisfying (CV = 3.44% and 2.33%; SEM = 1.70 and 2.16 kg for knee flexors and extensors, respectively).
Thera-Band is a valid and reliable alternative to the use of fitness equipment to test maximal strength of the knee flexors and extensors in healthy subjects. The ease of use, accessibility, and low cost of elastic bands should allow regular assessment during the rehabilitation process.