Search Results

You are looking at 1 - 10 of 36 items for :

  • "knee loading" x
Clear All
Restricted access

Li Jin, Peter G. Adamczyk, Michelle Roland and Michael E. Hahn

Lower limb amputation has been associated with secondary impairments such as knee osteoarthritis in the uninvolved limb. Greater knee loading in the frontal plane has been related to severity and rate of progression in knee osteoarthritis. Reduced push-off work from the involved limb can increase uninvolved limb knee loading. However, little is known about specific effects that prosthetic foot damping may have on uninvolved limb loading. We hypothesized that uninvolved limb peak knee internal abduction moment (IAM) and loading rates would be greater when using a high-damping foot compared with a low-damping foot, across walking speeds. Eight healthy, young subjects walked in a prosthesis simulator boot using the experimental feet. Greater uninvolved limb first peak IAM (+16% in fast speed, P = .002; +11% in slow speed, P = .001) and loading rates (+11% in fast speed, P = .003) were observed when using the high-damping foot compared with low-damping foot. Within each foot, uninvolved limb first peak IAM and loading rates had a trend to increase with increased walking speed. These findings suggest that damping properties of prosthetic feet are related to uninvolved limb peak knee IAM and loading rates.

Restricted access

Anh-Dung Nguyen, Jeffrey B. Taylor, Taylor G. Wimbish, Jennifer L. Keith and Kevin R. Ford

observed to land with greater knee extensor moments and lower hip extensor moments when compared with men 2 – 5 and with greater frontal plane knee abduction moments. 5 – 7 Of particular concern is the increase in frontal plane knee loading, as greater external knee abduction moments have been reported

Restricted access

Susana Meireles, Neil D. Reeves, Richard K. Jones, Colin R. Smith, Darryl G. Thelen and Ilse Jonkers

been deeply explored in OA with most studies in literature focusing on knee loading during level walking as a biomarker for OA onset and progression. Previous literature has shown reduced knee flexion moments (KFM), 4 , 7 , 9 nonconclusive findings in knee adduction moments (KAM), 4 , 10 and altered

Restricted access

Joaquin A. Barrios, Todd D. Royer and Irene S. Davis

Dynamic knee alignment is speculated to have a stronger relationship to medial knee loading than radiographic alignment. Therefore, we aimed to determine what frontal plane knee kinematic variable correlated most strongly to the knee adduction moment. That variable was then compared with radiographic alignment as a predictor of the knee adduction moment. Therefore, 55 subjects with medial knee OA underwent three-dimensional gait analysis. A subset of 21 subjects also underwent full-limb radiographic assessment for knee alignment. Correlations and regression analyses were performed to assess the relationships between the kinematic, kinetic and radiographic findings. Peak knee adduction angle most strongly correlated to the knee adduction moment of the kinematic variables. In comparison with radiographic alignment, peak knee adduction angle was the stronger predictor. Given that most epidemiological studies on knee OA use radiographic alignment in an attempt to understand progression, these results are meaningful.

Restricted access

Christopher M. Saliba, Allison L. Clouthier, Scott C.E. Brandon, Michael J. Rainbow and Kevin J. Deluzio

The onset and progression of knee osteoarthritis have been attributed to abnormal loading of the knee joint. 1 – 3 Clinical interventions, both surgical and noninvasive, aim to reduce medial compartment knee loads. 4 – 6 Gait retraining is a noninvasive intervention in the treatment of

Restricted access

Renato Semadeni and Kai-Uwe Schmitt

Objective:

In this study a numerical model of a skier was developed to investigate the effect of different rehabilitation strategies after anterior cruciate ligament (ACL) rupture.

Methods:

A computer model using a combined finite-element and multibody approach was established. The model includes a detailed representation of the knee structures, as well as all major leg muscles. Using this model, different strategies after ACL rupture were analyzed.

Results:

The benefit of muscle training to compensate for a loss of the ACL was shown. The results indicate that an increase of 10% of the physiological cross-sectional area has a positive effect without subjecting other knee structures to critical loads. Simulating the use of a hamstring graft indicated increasing knee loads. A patellar-tendon graft resulted in an increase of the stress on the lateral collateral ligament.

Conclusion:

Muscle training of both extensors and flexors is beneficial in medical rehabilitation of ACL-deficient and ACL-reconstructed knees.

Restricted access

Alasdair R. Dempsey, Bruce C. Elliott, Bridget J. Munro, Julie R. Steele and David G. Lloyd

Anterior cruciate ligament (ACL) injuries are costly. Sidestep technique training reduces knee moments that load the ACL. This study examined whether landing technique training alters knee moments. Nineteen team sport athletes completed the study. Motion analysis and ground reaction forces were recorded before and after 6 weeks of technique modification. An inverse dynamic model was used to calculate three-dimensional knee loading. Pre- and postintervention scores were compared using paired t tests. Maximal knee flexion angle during landing was increased following training. There was no change in valgus or flexion moments, but an increase in peak internal rotation moment. This increase in internal rotation moment may increase the risk of ACL injury. However, the increased angle at which the peak internal rotation moment occurred at follow up may mitigate any increase in injury risk by reducing load transmission.

Restricted access

Dorsey Shelton Williams and Wesley Isom

Knee varus position and motion have been correlated with increased medial knee loading during gait. The purpose of this study is to determine whether runners with excessive varus excursion (EVE) at the knee demonstrate frontal plane knee and hip kinetics that are different from those of runners with normal varus excursion (NVE). Twelve runners with EVE were compared with 12 NVE subjects using three-dimensional kinematics and kinetics. Frontal plane angles and moments were compared at the knee and hip. Runners with EVE had significantly greater abductor moment of the knee (p = .004) and lower peak abductor moment of the hip (p = .047). Runners with EVE demonstrate knee and hip mechanics thought to be associated with increased medial tibiofemoral loading. Further understanding of how changing hip abductor moments may affect changes in knee abductor moments during running may potentially lead to interventions that augment long-term risk of injury.

Restricted access

Jeffrey B. Wheeler, Robert J. Gregor and Jeffrey P. Broker

Pedal kinetics, including the applied moment (Mz) about an axis orthogonal to the pedal surface and passing through the center of pressure, were measured across three shoe/pedal interface systems (toe-clip and strap, clipless fixed, clipless float) and three workrates (150, 250, 350 W) during steady-state cycling using specially developed multicompatible force pedals. The applied moment (Mz) at the pedal is an important contributor to the corresponding axial moment realized at the knee and has implications for studying overuse injury mechanics and prevention of cycling-related knee pain. Data were collected from 27 knee pain free (KPF) cyclists and 7 cyclists with cycling-related knee pain. The largest applied moments (Mz) were observed when clipless fixed pedals were employed, while clipless float pedals significantly attenuated the applied moment. Cyclists with chronic knee pain exhibited Mz patterns markedly different from the KPF group, supporting the theory that relatively high moments, particularly internally applied moments during the power phase, may be related to knee loads and subsequent overuse injury. Our general conclusion is that clipless pedal float designs quantifiably reduce applied moments at the shoe/pedal interface without compromising power transmitted to the bike.

Restricted access

Stefan M. Gabriel, Anton G. Clifford, William J. Maloney, Mary K. O’Connell and Paul Tornetta III

Medial knee osteoarthritis (OA) is a common disorder often associated with pathologic joint loading. Insoles, braces, and high tibial osteotomy are OA treatments aimed at reducing medial joint loads, but their use and effectiveness are limited. The KineSpring System implant also intends to reduce knee loads in OA patients while overcoming those limitations. The current study was undertaken to test the implant’s effect on loads at the knee. Six cadaver knees with Outerbridge Grade I-II medial OA were subjected to simulated gait using a kinematic test system. Knees were tested with and without the medial knee implant while thin film sensors measured medial and lateral femorotibial contact pressures. Significant medial compartment load reductions (134 ± 53 N [P = .002]) were found throughout the stance phase of gait in the treated knee. Significant total joint load decreases (91 ± 40 N [P = .002]) were also observed without substantial changes in lateral compartment loads. These significant reductions of medial and total intra-articular loads are also within clinically effective ranges of other unloading systems. This suggests that the KineSpring System could be a viable treatment for medial knee OA.