Anterior cruciate ligament (ACL) reconstruction has been widely performed to treat patients with ACL injuries, and the overall outcomes were satisfactory in previous reports. 1 Although most patients regain knee stability and functional recovery after ACL reconstruction, 2 , 3 quadriceps strength
Yuya Ueda, Takehiko Matsushita, Yohei Shibata, Kohei Takiguchi, Akihiro Kida, Daisuke Araki, Noriyuki Kanzaki, Yuichi Hoshino, Rei Ono, Yoshitada Sakai and Ryosuke Kuroda
Felix Stief, Anna Schäfer, Lutz Vogt, Marietta Kirchner, Markus Hübscher, Christian Thiel, Winfried Banzer and Andrea Meurer
The present study should reveal differences in gait performance, quadriceps strength, and physical activity (PA) between fallers and nonfallers in women with osteoporosis. Forty-one women with osteoporosis (17 fallers, 24 nonfallers) participated. Gait analysis shows that fallers were walking with a slower walking speed (−9%, p = .033) and had a shorter stride length (−7%, p = .039). Moreover, fallers showed a decreased ankle power generation (−18%, p = .045). The quadriceps strength was decreased by 24% for fallers (p = .005) while PA showed no significant differences. Although a decrease in ankle power generation could have an effect on floor clearance for limb advancement in the swing phase, the causal relationship between spatiotemporal parameters (walking speed, stride length) and walking ankle joint power generation remains unknown and warrants further investigation. In conclusion, walking speed, stride length, ankle power generation, and quadriceps strength can be used to differentiate between fallers and nonfallers in women with osteoporosis.
Pier Paolo Mariani, Luca Laudani, Jacopo E. Rocchi, Arrigo Giombini and Andrea Macaluso
knee joint. Even if ACL reconstruction (ACLr) has shown good results in terms of knee stability, residual and persistent quadriceps strength deficit is reported as one of the limiting factors in return to preinjury level of function and activity, 1 – 4 and this deficit can persist for more than 2
Lindsey K. Lepley and Riann M. Palmieri-Smith
Interventions aimed at safely overloading the quadriceps muscle after anterior cruciate ligament (ACL) reconstruction are essential to reducing quadriceps muscle weakness that often persists long after the rehabilitation period. Despite the best efforts of clinicians and researchers to improve ACL rehabilitation techniques, a universally effective intervention to restore preinjury quadriceps strength has yet to be identified. A muscle’s force-producing capacity is most optimal when an external force exceeds that of the muscle while the muscle lengthens. Hence, the potential to improve muscle strength by overloading the tissue is greater with eccentric strengthening than with concentric strengthening. Traditionally, the application of early postoperative high-intensity eccentric resistance training to the ACL-reconstructed limb has been contraindicated, as there is potential for injury to the ACL graft, articular cartilage, or surrounding soft-tissue structures. However, recent evidence suggests that the application of early, progressive, high-force eccentric resistance exercises to the involved limb can be used to safely increase muscle volume and strength in ACL-reconstructed individuals. As a result, eccentric strengthening may be another attractive alternative to traditional concentric strengthening to improve quadriceps strength after ACL reconstruction.
Focused Clinical Question:
In patients who have undergone ACL reconstruction, is there evidence to suggest that eccentric exercise positively affects postoperative quadriceps strength?
Neal R. Glaviano and Susan Saliba
patellofemoral stress. 9 , 10 Researchers have examined whether weakness in the quadriceps or gluteus medius is a risk factor for the development of PFP. Isokinetic quadriceps strength has been suggested to be a predictor in the development of PFP. 11 , 12 However, isometric gluteus medius weakness has not been
Michelle M. McLeod, Phillip Gribble, Kate R. Pfile and Brian G. Pietrosimone
Arthroscopic partial meniscectomy (APM) after meniscal tear has been widely accepted and associated with quick return to activity. Unfortunately, meniscectomy is associated with risk for knee osteoarthritis, which may be attributed to postsurgical quadriceps weakness. This has important implications, as the quadriceps play a prominent role in knee stabilization and energy attenuation in the lower extremity.
To determine the magnitude of interlimb quadriceps strength deficits in people with unilateral APM by systematically reviewing the current literature.
The Web of Knowledge databases were searched on September 22, 2010, using terms meniscus OR meniscectomy AND quadriceps strength OR quadriceps weakness. Included articles were written in English, reporting means and SDs of isokinetic peak torque at 60° and 180°/s for both limbs.
Four articles were included in the final analysis. Effect sizes and 95% confidence intervals (CI) were calculated between limbs for periods less than 1 mo, 1–3 mo, 3–6 mo, and more than 6 mo.
Homogeneous effect sizes indicate quadriceps weakness in the involved limb. Effects were strong at less than 1 mo (d = −1.01 to −1.62), while weak to strong effects were found for 1–3 mo (d = −0.40 to −8.04) and 3–6 mo (d = −0.40 to −5.11). Weak effects were found at more than 6 mo (d = −0.30 to −0.37). Definitive effects with a CI not crossing zero were found in 65% of the data. Although APM patients return to function within weeks after surgery, prolonged quadriceps strength deficits may increase the risk of knee-joint degeneration. Furthermore, evidence of bilateral dysfunction after unilateral injury may suggest that neuromuscular deficits post-APM are greater than the interlimb differences found in this review. Further research should be conducted to determine the nature of strength deficits and the best methods for restoring strength after APM.
Brian G. Pietrosimone, Adam S. Lepley, Hayley M. Ericksen, Phillip A. Gribble and Jason Levine
Disability is common in a proportion of patients after anterior cruciate ligament reconstruction (ACL-R). Neuromuscular quadriceps deficits are a hallmark impairment after ACL-R, yet the link between muscle function and disability is not understood.
To evaluate the ability of quadriceps strength and cortical excitability to predict self-reported disability in patients with ACL-R.
Fifteen participants with a history of ACL-R (11 female, 4 male; 172 ± 9.8 cm, 70.4 ± 17.5 kg, 54.4 ± 40.9 mo postsurgery) were included in this study. Corticospinal excitability was assessed using active motor thresholds (AMT), while strength was assessed with maximal voluntary isometric contractions (MVIC). Both voluntary strength and corticospinal excitability were used to predict disability measured with the International Knee Documentation Committee Index (IKDC).
The overall multiple-regression model significantly predicted 66% of the variance in self-reported disability as measured by the IKDC index (R 2 = .66, P = .01). Initial imputation of MVIC into the model accounted for 61% (R 2 = .61, P = .01) of the variance in IKDC. The subsequent addition of AMT into the model accounted for an insignificant increase of 5% (Δ R 2 = .05, P = .19) in the prediction capability of the model.
Quadriceps voluntary strength and cortical excitability predicted two-thirds of the variance in disability of patients with ACL-R, with strength accounting for virtually all of the predictive capability of the model.
Sarah C. Moudy, Neale A. Tillin, Amy R. Sibley and Siobhán Strike
currently unknown how the intact limb may accommodate for decreased quadriceps strength. When landing from a jump, the time to develop muscular force to control joint motion is limited. Generation of rapid muscle force has been shown to be important for restabilization of the lower limb joints following
Gary B. Wilkerson
Lori A. Bolgla and Douglas R. Keskula
To provide information on research investigating the relationship between a knee effusion and quadriceps inhibition
Peer-reviewed publications from 1965 to 1997 that investigated the effect of a knee effusion on quadriceps strength.
The studies reviewed involved human subjects. Researchers have used active motion, electromyographic equipment, and isokinetics to measure changes in quadriceps strength after a knee effusion.
Most studies reported that a knee effusion resulted in quadriceps inhibition and inferred that quadriceps inhibition would impair knee function.
The authors believe that additional research is needed to better understand the effect of a knee effusion on knee function. Although a knee effusion might lead to quadriceps inhibition, other factors contribute to normal knee function and might allow enough compensation so that knee function is not affected significantly in the presence of certain effusions.