Biomechanics of the Knee during Closed Kinetic Chain and Open Kinetic Chain Exercises

American Sports Medicine Institute, Birmingham, AL 35205, USA.
Medicine &amp Science in Sports &amp Exercise (Impact Factor: 3.98). 05/1998; 30(4):556-69. DOI: 10.1097/00005768-199804000-00014
Source: PubMed


Although closed (CKCE) and open (OKCE) kinetic chain exercises are used in athletic training and clinical environments, few studies have compared knee joint biomechanics while these exercises are performed dynamically. The purpose of this study was to quantify knee forces and muscle activity in CKCE (squat and leg press) and OKCE (knee extension).
Ten male subjects performed three repetitions of each exercise at their 12-repetition maximum. Kinematic, kinetic, and electromyographic data were calculated using video cameras (60 Hz), force transducers (960 Hz), and EMG (960 Hz). Mathematical muscle modeling and optimization techniques were employed to estimate internal muscle forces.
Overall, the squat generated approximately twice as much hamstring activity as the leg press and knee extensions. Quadriceps muscle activity was greatest in CKCE when the knee was near full flexion and in OKCE when the knee was near full extension. OKCE produced more rectus femoris activity while CKCE produced more vasti muscle activity. Tibiofemoral compressive force was greatest in CKCE near full flexion and in OKCE near full extension. Peak tension in the posterior cruciate ligament was approximately twice as great in CKCE, and increased with knee flexion. Tension in the anterior cruciate ligament was present only in OKCE, and occurred near full extension. Patellofemoral compressive force was greatest in CKCE near full flexion and in the mid-range of the knee extending phase in OKCE.
An understanding of these results can help in choosing appropriate exercises for rehabilitation and training.

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    • "Contrary to the present findings, GM was not the last muscle to be recruited and the discrepancy may be explained by variations in methodology; the prone hip extension is classified as an open chain nonweight bearing exercise and DL, is an orthostatic, closed chain weight-bearing exercise. It is likely that open and closed chain exercises have different muscle strategies; for example, Escamilla et al. (1998) observed hamstring EMG activity was doubled during 12 RM barbell squat (closed chain exercise) compared with 12 RM seated knee extension (open chain exercise). Lehman et al. (2004) have expressed concerns with the use of the prone hip extension and have argued for additional functional exercises to be assessed. "
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    ABSTRACT: The aim of this study was to determine the muscle activity and onset time of hip extensors during a closed kinetic chain exercise (deadlift) at sub-maximal loads of 30%, 40%, 50%, and 75% of one repetition maximum (1RM). Twelve healthy males with at least three years of resistance training experience volunteered for the study. Biceps femoris (BF) and gluteus maximus (GM) muscle activity, onset time, peak and mean power were measured during the concentric phase of the deadlift. There was no main effect (p > 0.05) or no interaction effect for the onset time in BF and GM and for each load BF and GM had similar muscle activity. Increasing the external load during deadlift had no adverse effect on the relative onset time and it did not promote BF onset to occur before GM onset, thus both muscles were simultaneously activated, which should not compromise a delay in GM.
    Research in Sports Medicine 02/2015; 23(2):1-11. DOI:10.1080/15438627.2015.1005299 · 1.70 Impact Factor
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    • "sEMG) during the extension and flexion actions of the leg muscles was recorded from the vastus lateralis (VL), vastus medialis (VM) and the short head of the bicep femoris (BF) of the right leg by a pair of bipolar surface electrodes (Blue Sensor N-00-S, Medicotest) with a distance between the electrode's centres of 22 mm. The agonists vastus lateralis (VL) and vastus medialis (VM) muscles were averaged because they have demonstrated similar patterns of activation during bilateral leg press exercise (Escamilla et al. 1998 "

    • "In squat exercises, the lowest possible resistance is the subject's weight, while during leg extension, the subject's weight is not an important factor and subjects can adjust the resistance by increasing the stiffness of springs, thus allowing weak individuals or individuals in rehabilitation, to perform leg extensor strengthening in a gentle manner that would not be possible with squat exercises. Furthermore, joint moments in the squat are extensor in both knee and hip throughout the exercise (Escamilla et al., 1998). While leg extensions on the Reformer may be performed using continuous hip and knee extensor moments, the exercise may also be performed with extension moments at one joint and flexion moments at the other, as we showed here for the first time. "
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    ABSTRACT: Considering the kinematics of leg extensions performed on a Reformer apparatus, one would expect high activation of hip and knee extensor muscle groups. However, because of the bi-articular nature of some lower limb muscles, and the possibility to vary the direction of force application on the Reformer bar, muscles can be coordinated theoretically in a variety of ways and still achieve the desired outcome. Hence, the aim of this study was to determine the knee and hip moments during leg extensions performed on the Reformer apparatus and to estimate the forces in individual muscles crossing these joints using static optimization. Fifteen subjects performed leg extensions exercises on the Reformer apparatus using an individually chosen resistance. To our big surprise, we found that subjects performed the exercise using two conceptually different strategies (i) the first group used simultaneous hip and knee extension moments, (ii) while the second group used simultaneous hip flexion and knee extension moments to perform the exercise. These different strategies were achieved by changing the direction of the resultant force applied by the subject’s feet on the Reformer bar. While leg extensions on the Reformer apparatus have been thought to strengthen the hip and knee extensors muscles, our results demonstrate that patients can perform the exercise in a different and unexpected way. In order to control the hip and knee moments and achieve the desired outcome of the exercise, the direction of force application on the Reformer bar must be controlled carefully.
    Journal of Electromyography and Kinesiology 09/2014; 25(2). DOI:10.1016/j.jelekin.2014.08.016 · 1.65 Impact Factor
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