force was also observed in those subjects during step-by-step in comparison to step-over-step either during stair ascent or descent. 23 To date, it is still unknown how the altered stair negotiation patterns observed in individuals with knee OA affect the compartmental knee contact forces (KCF) as only
Susana Meireles, Neil D. Reeves, Richard K. Jones, Colin R. Smith, Darryl G. Thelen and Ilse Jonkers
Shinya Ogaya, Hisashi Naito, Akira Iwata, Yumi Higuchi, Satoshi Fuchioka and Masao Tanaka
Toe-out angle alternation is a potential tactic for decreasing the knee adduction moment during walking. Published reports have not examined the medial knee contact force during the toe-out gait, although it is a factor affecting knee articular cartilage damage. This study investigated the effects of increased toe-out angle on the medial knee contact force, using musculoskeletal simulation analysis. For normal and toe-out gaits in 18 healthy subjects, the muscle tension forces were simulated based on the joint moments and ground reaction forces with optimization process. The medial knee contact force during stance phase was determined using the sum of the muscle force and joint reaction force components. The first and second peaks of the medial knee contact force were compared between the gaits. The toe-out gait showed a significant decrease in the medial knee contact force at the second peak, compared with the normal gait. In contrast, the medial knee contact forces at the first peak were not significantly different between the gaits. These results suggest that the toe-out gait is beneficial for decreasing the second peak of the medial knee contact force.
Christopher M. Saliba, Allison L. Clouthier, Scott C.E. Brandon, Michael J. Rainbow and Kevin J. Deluzio
Abnormal loading of the knee joint contributes to the pathogenesis of knee osteoarthritis. Gait retraining is a noninvasive intervention that aims to reduce knee loads by providing audible, visual, or haptic feedback of gait parameters. The computational expense of joint contact force prediction has limited real-time feedback to surrogate measures of the contact force, such as the knee adduction moment. We developed a method to predict knee joint contact forces using motion analysis and a statistical regression model that can be implemented in near real-time. Gait waveform variables were deconstructed using principal component analysis, and a linear regression was used to predict the principal component scores of the contact force waveforms. Knee joint contact force waveforms were reconstructed using the predicted scores. We tested our method using a heterogenous population of asymptomatic controls and subjects with knee osteoarthritis. The reconstructed contact force waveforms had mean (SD) root mean square differences of 0.17 (0.05) bodyweight compared with the contact forces predicted by a musculoskeletal model. Our method successfully predicted subject-specific shape features of contact force waveforms and is a potentially powerful tool in biofeedback and clinical gait analysis.
Oladipo O. Eddo, Bryndan W. Lindsey, Shane V. Caswell, Matt Prebble and Nelson Cortes
exist. 19 These results indicate that the optimal gait modification strategy and effective magnitude might differ between individuals. Reduced peak KAM in individuals with knee OA is associated with decreased medial knee contact force, 11 which results in decreased pain, increased function, and
Chad Van Ramshorst and Woochol Joseph Choi
and tendonitis). Therefore, it is necessary to understand the characteristics of knee contact forces involved in choreographed falls to provide further insight into the cause of these injuries in dancers. Against this background, choreographed-falling experiments were conducted with young, collegiate
Niell G. Elvin, Alex A. Elvin, Steven P. Arnoczky and Michael R. Torry
Impact forces and shock deceleration during jumping and running have been associated with various knee injury etiologies. This study investigates the influence of jump height and knee contact angle on peak ground reaction force and segment axial accelerations. Ground reaction force, segment axial acceleration, and knee angles were measured for 6 male subjects during vertical jumping. A simple spring-mass model is used to predict the landing stiffness at impact as a function of (1) jump height, (2) peak impact force, (3) peak tibial axial acceleration, (4) peak thigh axial acceleration, and (5) peak trunk axial acceleration. Using a nonlinear least square fit, a strong (r = 0.86) and significant (p ≤ 0.05) correlation was found between knee contact angle and stiffness calculated using the peak impact force and jump height. The same model also showed that the correlation was strong (r = 0.81) and significant (p ≤ 0.05) between knee contact angle and stiffness calculated from the peak trunk axial accelerations. The correlation was weaker for the peak thigh (r = 0.71) and tibial (r = 0.45) axial accelerations. Using the peak force but neglecting jump height in the model, produces significantly worse correlation (r = 0.58). It was concluded that knee contact angle significantly influences both peak ground reaction forces and segment accelerations. However, owing to the nonlinear relationship, peak forces and segment accelerations change more rapidly at smaller knee flexion angles (i.e., close to full extension) than at greater knee flexion angles.
Max R. Paquette, Audrey Zucker-Levin, Paul DeVita, Joseph Hoekstra and David Pearsall
The purpose of this study was to compare lower extremity joint angular position and muscle activity during elliptical exercise using different foot positions and also during exercise on a lateral elliptical trainer. Sixteen men exercised on a lateral elliptical and on a standard elliptical trainer using straight foot position, increased toe-out angle, and a wide step. Motion capture and electromyography systems were used to obtain 3D lower extremity joint kinematics and muscle activity, respectively. The lateral trainer produced greater sagittal and frontal plane knee range of motion (ROM), greater peak knee flexion and extension, and higher vastus medialis activation compared with other conditions (P < .05). Toe-out and wide step produced the greatest and smallest peak knee adduction angles, respectively (P < .05). The lateral trainer produced greater sagittal and frontal plane hip ROM and greater peak hip extension and flexion compared with all other conditions (P < .05). Toe-out angle produced the largest peak hip external rotation angle and lowest gluteus muscle activation (P < .05). Findings from this study indicate that standard elliptical exercise with wide step may place the knee joint in a desirable frontal plane angular position to reduce medial knee loads, and that lateral elliptical exercise could help improve quadriceps strength but could also lead to larger knee contact forces.
Cherice N. Hughes-Oliver, Kathryn A. Harrison, D.S. Blaise Williams III and Robin M. Queen
, Snyder-Mackler L . Knee contact force asymmetries in patients who failed return-to-sport readiness criteria 6 months after anterior cruciate ligament reconstruction . Am J Sports Med . 2014 ; 42 ( 12 ): 2917 – 2925 . PubMed ID: 25318940 doi:10.1177/0363546514552184 10.1177/0363546514552184 25318940
Christie Powell, Jody Jensen and Samantha Johnson
with ACLR demonstrated abnormal knee contact forces during gait and return-to-sport testing with significant and meaningful joint contact force asymmetries noted during single-leg hop testing. 8 These patients failed return-to-sport criteria at 6 months after ACLR, indicating increased risk for
Stefan Sebastian Tomescu, Ryan Bakker, Tyson A.C. Beach and Naveen Chandrashekar
.5) 6.4 (1.6) 6.5 (1.7) <.01* BDEF Max hamstring force, Bw 2.3 (1.2) 2.5 (1.2) 3.5 (0.5) 3.6 (0.6) <.01* BDEF Max gastrocnemius force, Bw 1.8 (0.5) 1.8 (0.4) 3.2 (0.7) 2.9 (0.6) <.01* BDEF Peak ankle contact forces b , Bw 10.6 (1.9) 11.0 (2.1) 13.0 (2.4) 12.9 (2.5) <.01* BDEF Peak knee contact forces b