Tibiofemoral Joint Contact Forces Research Articles

The effect of impaired unilateral ankle propulsion on contralateral knee joint loading

BackgroundImpairments in unilateral ankle propulsion may result from restriction by an external device or pathology such as lower limb amputation. Models of gait suggest this reduction may lead to increased collisional force on the contralateral side, potentially increasing force through the knee and increasing the risk of knee pain or osteoarthritis. Research questionHow do restrictions in unilateral ankle propulsive force affect contralateral knee joint loading in otherwise healthy individuals? Methods18 individuals without impairment walked on a treadmill at 1.5 m/s for two conditions: one free of restrictions, and one where a randomized limb’s ankle propulsive force was restricted using an off-the-shelf ankle-foot orthosis (AFO). Ankle propulsive power, lower extremity joint work, and ground reaction force variables were calculated for the final 3 gait cycles of each condition. Tibiofemoral joint contact force (TJCF) for the limb contralateral to the AFO was calculated through a standard OpenSim workflow utilizing the gait2392 model. Intra-limb pair-wise comparisons were made between conditions. ResultsCompared to walking unrestricted, the limb wearing the AFO demonstrated a significant reduction in peak ankle propulsive power and positive ankle work by approximately 50 % each (p<0.01). With ankle restriction, the ipsilateral knee significantly increased positive work (p<0.01). The overall propulsion produced by that limb did not change between conditions, demonstrated by a lack of change in anterior ground reaction force impulse (p=0.11). The knee of the limb contralateral to the AFO did not display differences in any TJCF variable between conditions (all p>0.07). SignificanceThese results suggest a unilateral deficit in ankle propulsion will not increase contralateral knee joint forces in individuals who are able to use other joints of the limb to compensate for the loss of ankle function. However, further research should investigate this relationship in those who display pathologies that may prevent more proximal compensations.

Periarticular muscle status affects in vivo tibio-femoral joint loads after total knee arthroplasty.

Background: Total knee arthroplasty (TKA) is a highly effective treatment for severe knee osteoarthritis that is increasingly performed in younger, more active patients. As postoperative muscular impairments may negatively affect surgical outcomes and implant longevity, functional muscle recovery gains increasing importance in meeting future patient demands. This study aimed to assess the status of periarticular muscles in the long-term follow-up after TKA and to evaluate its impact on in vivo tibio-femoral joint loads. Methods: A case series was created, with eight patients with knee osteoarthritis. All subjects received an instrumented knee implant in unilateral TKA. Native computed tomography scans, acquired pre and postoperatively, were used to evaluate distal muscle volumes and fatty infiltration. In vivo tibio-femoral joint loads were measured telemetrically during standing, walking, stair climbing and chair rising and were correlated to muscle status. Results: Postoperatively a reduction in fatty infiltration across all periarticular muscles was pronounced. High average peak loads acted in the tibio-femoral joint ranging from 264% during stand-to-sit activities up to 341% body weight (BW) during stair descent. Fatty infiltration of the m. quadriceps femoris and hamstrings were associated with increased tibio-femoral joint contact forces during walking (r = 0.542; 0.412 and 0.766). Conclusion: The findings suggest that a fatty infiltration of periarticular muscles may lead to increased tibio-femoral joint contact forces. However, we only observed weak correlations between these parameters. Improvements in functional mobility and the restoration of a pain-free joint likely explain the observed postoperative reductions in fatty infiltration. Perioperative rehabilitation approaches targeting residual impairments in muscle quality could, contribute to reduced tibio-femoral joint loads and improved long-term outcomes of TKA. However, it has to be pointed out that the study included a small number of patients, which may limit its validity.

High tibiofemoral contact and muscle forces during gait are associated with radiographic knee OA progression over 3 years

BackgroundThe objective of this study was to investigate differences in tibiofemoral joint contact forces between individuals with moderate medial OA who exhibit radiographic knee OA progression within 3 years versus those who do not, and to understand the relationship between model-predicted contact forces and net external moments for this population. Methods27 individuals with moderate medial compartment knee OA underwent baseline instrumented gait analysis. OA progressors were defined as those who experienced at least a one grade increase in medial joint space narrowing at three years. An electromyography-driven musculoskeletal model was used to estimate muscle and tibiofemoral contact forces at baseline, which were compared between progressors and non-progressors using t-tests. ResultsSeven individuals experienced radiographic OA progression by 3 years. Progressors walked with significantly higher peaks of medial and total tibiofemoral contact forces, and higher impulse of medial contact forces. Significant and high correlations were found between: first peaks of medial and total contact forces with first peak of the knee adduction moment (R2 = 0.74; R2 = 0.59); second peaks of medial and total knee contact forces with second peaks of knee adduction and flexion moments (R2 = 0.71; R2 = 0.68); medial knee contact force impulse with knee adduction moment impulse (R2 = 0.76). ConclusionsHigher tibiofemoral joint contact forces during walking were associated with three-year radiographic knee OA progression based on medial joint space narrowing. These results support the need for strategies that reduce compressive knee contact forces through the reduction of adduction and flexion moments during walking.

Tibiofemoral Load Magnitude and Distribution During Load Carriage.

Chronic exposure to high tibiofemoral joint (TFJ) contact forces can be detrimental to knee joint health. Load carriage increases TFJ contact forces, but it is unclear whether medial and lateral tibiofemoral compartments respond similarly to incremental load carriage. The purpose of our study was to compare TFJ contact forces when walking with 15% and 30% added body weight. Young healthy adults (n = 24) walked for 5minutes with no load, 15% load, and 30% load on an instrumented treadmill. Total, medial, and lateral TFJ contact peak forces and impulses were calculated via an inverse dynamics informed musculoskeletal model. Results of 1-way repeated measures analyses of variance (α = .05) demonstrated total, medial, and lateral TFJ first peak contact forces and impulses increased significantly with increasing load. Orthogonal polynomial trends demonstrated that the 30% loading condition led to a curvilinear increase in total and lateral TFJ impulses, whereas medial first peak TFJ contact forces and impulses responded linearly to increasing load. The total and lateral compartment impulse increased disproportionally with load carriage, while the medial did not. The medial and lateral compartments responded differently to increasing load during walking, warranting further investigation because it may relate to risk of osteoarthritis.

Alterations in the Functional Knee Alignment Are Not an Effective Strategy to Modify the Mediolateral Distribution of Knee Forces During Closed Kinetic Chain Exercises.

Pain felt while performing rehabilitation exercises could be a reason for the low adherence of knee osteoarthritis patients to physical rehabilitation. Reducing compressive forces on the most affected knee regions may help to mitigate the pain. Knee frontal plane positioning with respect to pelvis and foot (functional knee alignment) has been shown to modify the mediolateral distribution of the tibiofemoral joint contact force in walking. Hence, different functional knee alignments could be potentially used to modify joint loading during rehabilitation exercises. The aim was to understand whether utilizing different alignments is an effective strategy to unload specific knee areas while performing rehabilitation exercises. Eight healthy volunteers performed 5 exercises with neutral, medial, and lateral knee alignment. A musculoskeletal model was modified for improved prediction of tibiofemoral contact forces and used to evaluate knee joint kinematics, moments, and contact forces. Functional knee alignment had only a small and inconsistent effect on the mediolateral distribution joint contact force. Moreover, the magnitude of tibiofemoral and patellofemoral contact forces, knee moments, and measured muscle activities was not significantly affected by the alignment. Our results suggest that altering the functional knee alignment is not an effective strategy to unload specific knee regions in physical rehabilitation.

Computer-based analysis of different component positions and insert thicknesses on tibio-femoral and patello-femoral joint dynamics after cruciate-retaining total knee replacement

BackgroundPositioning of the implant components and tibial insert thickness constitute critical aspects of total knee replacement (TKR) that influence the postoperative knee joint dynamics. This study aimed to investigate the impact of implant component positioning (anterior-posterior and medio-lateral shift) and varying tibial insert thickness on the tibio-femoral (TF) and patello-femoral (PF) joint kinematics and contact forces after cruciate-retaining (CR)-TKR. MethodA validated musculoskeletal multibody simulation (MMBS) model with a fixed-bearing CR-TKR during a squat motion up to 90° knee flexion was deployed to calculate PF and TF joint dynamics for varied implant component positions and tibial insert thicknesses. Evaluation was performed consecutively by comparing the respective knee joint parameters (e.g. contact force, quadriceps muscle force, joint kinematics) to a reference implant position. ResultsThe PF contact forces were mostly affected by the anterior-posterior as well as medio-lateral positioning of the femoral component (by 3 mm anterior up to 31 % and by 6 mm lateral up to 14 %). TF contact forces were considerably altered by tibial insert thickness (24 % in case of + 4 mm increase) and by the anterior-posterior position of the femoral component (by 3 mm posterior up to 16 %). Concerning PF kinematics, a medialised femoral component by 6 mm increased the lateral patellar tilt by more than 5°. ConclusionsOur results indicate that regarding PF kinematics and contact forces the positioning of the femoral component was more critical than the tibial component. The positioning of the femoral component in anterior-posterior direction on and PF contact force was evident. Orthopaedic surgeons should strictly monitor the anterior-posterior as well as the medio-lateral position of the femoral component and the insert thickness.

Effect of functional weightbearing versus non-weightbearing quadriceps strengthening exercise on contact force in varus-malaligned medial knee osteoarthritis: A secondary analysis of a randomized controlled trial

BackgroundKnee osteoarthritis progression may be related to altered knee loads, particularly in those with varus malalignment. Using randomized controlled trial data, this secondary analysis of complete datasets (n = 67) compared the effects of a functional weightbearing (WB) and non-weightbearing quadriceps strengthening exercise (NWB) program on measures of medial tibiofemoral joint contact force (MTCF) during walking. MethodsParticipants aged ≥50 years and with medial knee osteoarthritis and varus malalignment were randomly allocated to a 12-week, home-based, physiotherapist-prescribed exercise program comprised of WB exercises (n = 31), or NWB exercise (n = 36). Three-dimensional lower-body motion, ground reaction forces, and surface electromyograms from six lower-limb muscles were acquired during walking at baseline and at 12-weeks follow-up. An electromyogram-informed neuromusculoskeletal model estimated bodyweight (BW) normalized MTCF (peak and impulse), including external and muscular contributions to MTCF. ResultsThere was no between-group difference in the change in peak MTCF (−0.02 [−0.12, 0.09] BW) or MTCF impulse (−0.01 [−0.06, 0.03] BW·s). There was a between-group difference in the muscle contribution to peak MTCF (−0.08 [−0.15, −0.00] BW) and MTCF impulse (−0.04 [−0.08, −0.00] BW·s), whereby the muscle contribution reduced more in the NWB group over time compared to the WB group. There was also a between group-difference in the external contribution to peak MTCF (0.09 [0.01, 0.18] BW), but this reduced more in the WB group than in the NWB group. ConclusionsOur findings suggest no difference in MTCF between the two exercise programs, but differences in the contribution to MTCF between the two exercise programs were observed in those with medial knee osteoarthritis and varus malalignment.

Knee Joint Loading And Realtime Vertical Ground Reaction Force Biofeedback With Vest-Borne Loads

Realtime biofeedback has been used to modify gait and decrease knee joint loading. Vertical ground reaction force (vGRF) may offer broad utility as a feedback option to alter tibiofemoral joint (TFJ) contact forces during gait. For example, individuals that carry heavy loads experience increased TFJ contact force. vGRF feedback may reduce effect at the TFJ. PURPOSE: To investigate the effectiveness of vGRF feedback for reducing axial TFJ contact force during load carriage. METHODS: Twelve healthy adults (22 + 1.6 yrs), walked for 5 minutes per condition at 1.4 m·s-1 on an instrumented treadmill while carrying vest borne loads of 0%, 15%, and 30% body weight during 3D motion capture, with and without vGRF feedback to reduce peak vGRF below a set threshold. Hip, knee, and ankle kinematic and kinetic data were used as inputs to an inverse dynamics informed musculoskeletal model of axial TFJ contact force. Comparisons of peak TFJ contact force were made via 3x2 repeated measures ANOVA and post hoc paired T-Tests. RESULTS: vGRF feedback led to a total peak TFJ contact force increase of 25% at no load, 55% at 15% load, and 82% at 30% load as compared to no load no feedback. Each load condition with feedback elicited greater peak TFJ contact force than no feedback. (0% [3.44 vs 4.30 Body Weights (BW), p = 0.008]; 15% [3.92 vs 5.34 BW, p = 0.002]; 30% [4.55 vs 6.27 BW, p < 0.001], Figure 1). CONCLUSION: To reduce peak vGRF, participants slightly reduced their stride length and adopted a crouched gait characterized by increased knee and hip flexion. The increase in flexion increased estimated quadriceps and hamstrings force, ultimately leading to large increases in total TFJ contact forces. Although readily available than more sophisticated options to alter TFJ contact force, feedback of peak vGRF is not effective for reducing TFJ contact force with or without load carriage. Realtime feedback of TFJ contact forces would likely be an optimal choice of feedback if attempting to decrease knee joint loads.

Knee Joint Loading Distribution With Vest-borne Loads

Vest borne loads increase tibiofemoral joint (TFJ) contact forces, but the TFJ contact forces do not always increase proportionally to the increase in load (Lenton et al., 2018). It is unclear if and how increase in TFJ contact forces are attenuated during load carriage.PURPOSE: To determine the effects of load carriage on total, medial (MTFJ), and lateral (LTFJ) tibiofemoral joint contact forces, and to determine if increases in joint loads are attenuated via gait adaptations. METHODS: Twelve young, healthy adults (6 males [BMI = 22.19] and 6 females [BMI = 20.38]; 22 + 1.6 yrs), walked for 5 minutes per condition at 1.4 m·s-1 on an instrumented treadmill while carrying vest borne loads of 0%, 15%, and 30% body weight during 3D motion capture. Hip, knee, and ankle kinematic and kinetic data were used as inputs to an inverse-dynamics informed musculoskeletal model of axial TFJ contact force. Kinematic and TFJ contact force comparisons were made via repeated measures ANOVA. RESULTS: From 0% load to 15% and from 0% to 30%, total peak TFJ increased 14% and 32% (3.44 vs 3.92 vs 4.55 body weights (BW) p < 0.001); peak MTFJ increased 12% and 26.5% (2.42 vs 2.72 vs 3.05 BW, p < 0.001); peak LTFJ increased 13% and 38% (1.29 vs 1.46 vs 1.79 BW, p < 0.001), and leg stiffness decreased 10% and 28% (7.17 vs 6.46 vs 5.10 N/mm, p < 0.001), respectively. CONCLUSION: Young, healthy participants do not attenuate the increase in total and medial knee joint contact forces with increasing magnitude of load carriage. They respond to load by decreasing joint stiffness through small increases in dorsiflexion, knee flexion, and hip flexion, which does increase shock absorption and assists with energy transfer (Kinoshital, 1985). These minor increases in flexion coupled with increases in vertical ground reaction forces led to the approximately proportional relative percent increase in TFJ and MTFJ as compared to the increase in load. However, the increase in LTFJ from 0% load to 30% load was 8% greater indicating a disproportional increase in the lateral compartment, assuming that “disproportional” is greater or less than 5%. Further research should investigate if greater increases in load magnitude continue to lead to proportional increases in total TFJ and MTFJ, and disproportional increases LTFJ, especially in military populations who frequently carry heavy loads.

Estimation of Tibiofemoral Joint Contact Forces Using Foot Loads during Continuous Passive Motions.

Continuous passive motion (CPM) machines are commonly used after various knee surgeries, but information on tibiofemoral forces (TFFs) during CPM cycles is limited. This study aimed to explore the changing trend of TFFs during CPM cycles under various ranges of motion (ROM) and body weights (BW) by establishing a two-dimensional mathematical model. TFFs were estimated by using joint angles, foot load, and leg–foot weight. Eleven healthy male participants were tested with ROM ranging from 0° to 120°. The values of the peak TFFs during knee flexion were higher than those during knee extension, varying nonlinearly with ROM. BW had a significant main effect on the peak TFFs and tibiofemoral shear forces, while ROM had a limited effect on the peak TFFs. No significant interaction effects were observed between BW and ROM for each peak TFF, whereas a strong linear correlation existed between the peak tibiofemoral compressive forces (TFCFs) and the peak resultant TFFs (R2 = 0.971, p < 0.01). The proposed method showed promise in serving as an input for optimizing rehabilitation devices.

Effect of a valgus brace on medial tibiofemoral joint contact force in knee osteoarthritis with varus malalignment: A within-participant cross-over randomised study with an uncontrolled observational longitudinal follow-up.

BackgroundPrevious investigations on valgus knee bracing have mostly used the external knee adduction moment. This is a critical limitation, as the external knee adduction moment does not account for muscle forces that contribute substantially to the medial tibiofemoral contact force (MTCF) during walking. The aims of this pilot study were to: 1) determine the effect of a valgus knee brace on MTCF; 2) determine whether the effect is more pronounced after 8 weeks of brace use; 3) assess the feasibility of an 8-week brace intervention.MethodsParticipants with medial radiographic knee OA and varus malalignment were fitted with an Össur Unloader One© brace. Participants were instructed to wear the brace for 8 weeks. The MTCF was estimated via an electromyogram-assisted neuromuscular model with and without the knee brace at week 0 and week 8. Feasibility outcomes included change in symptoms, quality of life, confidence, acceptability, adherence and adverse events.ResultsOf the 30 (60% male) participants enrolled, 28 (93%) completed 8-week outcome assessments. There was a main effect of the brace (p<0.001) on peak MTCF and MTCF impulse, but no main effect for time (week 0 and week 8, p = 0.10), and no interaction between brace and time (p = 0.62). Wearing the brace during walking significantly reduced the peak MTCF (-0.05 BW 95%CI [-0.10, -0.01]) and MTCF impulse (-0.07 BW.s 95%CI [-0.09, -0.05]). Symptoms and quality of life improved by clinically relevant magnitudes over the 8-week intervention. Items relating to confidence and acceptability were rated relatively highly. Participants wore the brace on average 6 hrs per day. Seventeen participants reported 30 minor adverse events over an 8-week period.ConclusionAlthough significant, reductions in the peak MTCF and MTCF while wearing the knee brace were small. No effect of time on MTCF was observed. Although there were numerous minor adverse events, feasibility outcomes were generally favourable.Trial registrationAustralian and New Zealand Clinical Trials Registry (12619000622101).

Tibiofemoral joint contact forces during gait differ with radiographic knee oa progression over 3 years

Purpose: Forces on joint tissues during activities of daily living such as walking have been implicated in the progression of knee osteoarthritis (OA), however the relationship between force characteristics with osteoarthritis processes is complex. It remains unclear why knee OA progresses more quickly for some individuals, and if person-specific mechanics are an important factor. Most past investigations have reported net resultant joint moments calculated through an inverse dynamics procedure that provide a net summary of joint kinetics.

The influence of pain on tibiofemoral joint contact force and muscle forces in knee osteoarthritis patients during stair ascent

AbstractThis study investigated the tibiofemoral joint (TFJ) forces and supporting muscle forces displayed by knee osteoarthritis (OA) patients during stair ascent, and if these forces were influenced by the presence of pain. Fifteen knee OA patients partitioned into two groups based on pain experienced during stair ascent trails using a Visual Analogue Scale (VAS) (OA‐pain = 10; OA‐no pain = 5) and 14 healthy aged‐matched controls took part in this study. Kinematic and kinetic data were collected during three stair ascent trials, which provided the inputs for the musculoskeletal model FreeBody. TFJ contact forces and muscles forces were predicted by the model at early, mid‐ and late stance. These variables were compared between groups using a one‐way analysis of variance. The results show the OA‐pain (P &lt; .05; d = 2.4) and OA‐no pain (P &lt; .05; d = 1.1) groups displayed reduced medial TFJ contact forces and altered muscle forces in comparison to healthy controls during early stance. This suggests pain and the anticipation of pain results in knee OA patients deliberately offloading the front limb during stair ascent, which alters supporting muscle forces. This study provides valuable information on knee OA mechanics during stair ascent for clinicians developing rehabilitation programs.

Effect of exercise on knee joint contact forces in people following medial partial meniscectomy: A secondary analysis of a randomised controlled trial

BackgroundArthroscopic partial meniscectomy may cause knee osteoarthritis, which may be related to altered joint loading. Previous research has failed to demonstrate that exercise can reduce medial compartment knee loads following meniscectomy but has not considered muscular loading in their estimates. Research questionWhat is the effect of exercise compared to no intervention on peak medial tibiofemoral joint contact force during walking using an electromyogram-driven neuromusculoskeletal model, following medial arthroscopic partial meniscectomy? MethodsThis is a secondary analysis of a randomized controlled trial (RCT). 41 participants aged between 30–50 years with medial arthroscopic partial meniscectomy within the past 3–12 months, were randomly allocated to either a 12-week, home-based, physiotherapist-guided exercise program or to no exercise (control group). Three-dimensional lower-body motion, ground reaction forces, and surface electromyograms from eight lower-limb muscles were acquired during self-selected normal- and fast-paced walking at baseline and follow-up. An electromyogram-driven neuromusculoskeletal model estimated medial compartment contact forces (body weight). Linear regression models evaluated between-group differences (mean difference (95% CI)). ResultsThere were no significant between-group differences in the change (follow-up minus baseline) in first peak medial contact force during self-selected normal- or fast-paced walking (0.07 (−0.08 to 0.23), P = 0.34 and 0.01 (−0.19 to 0.22), P = 0.89 respectively). No significant between-group difference was found for change in second peak medial contact force during normal- or fast-paced walking (0.09 (−0.09 to 0.28), P = 0.31 and 0.02 (−0.17 to 0.22), P = 0.81 respectively). At the individual level, variability was observed for changes in first (range −26.2% to +31.7%) and second (range −46.5% to +59.9%) peak tibiofemoral contact force. SignificanceThis is the first study to apply electromyogram-driven neuromusculoskeletal modelling to an exercise intervention in a RCT. While our results suggest that a 12-week exercise program does not alter peak medial knee loads after meniscectomy, within-participant variability suggests individual-specific muscle activation patterns that warrant further investigation.

Immediate Effects of Medially Posted Insoles on Lower Limb Joint Contact Forces in Adult Acquired Flatfoot: A Pilot Study.

Flatfoot is linked to secondary lower limb joint problems, such as patellofemoral pain. This study aimed to investigate the influence of medial posting insoles on the joint mechanics of the lower extremity in adults with flatfoot. Gait analysis was performed on fifteen young adults with flatfoot under two conditions: walking with shoes and foot orthoses (WSFO), and walking with shoes (WS) in random order. The data collected by a vicon system were used to drive the musculoskeletal model to estimate the hip, patellofemoral, ankle, medial and lateral tibiofemoral joint contact forces. The joint contact forces in WSFO and WS conditions were compared. Compared to the WS group, the second peak patellofemoral contact force (p < 0.05) and the peak ankle contact force (p < 0.05) were significantly lower in the WSFO group by 10.2% and 6.8%, respectively. The foot orthosis significantly reduced the peak ankle eversion angle (p < 0.05) and ankle eversion moment (p < 0.05); however, the peak knee adduction moment increased (p < 0.05). The reduction in the patellofemoral joint force and ankle contact force could potentially inhibit flatfoot-induced lower limb joint problems, despite a greater knee adduction moment.

Development and Evaluation of a Subject-Specific Lower Limb Model With an Eleven-Degrees-of-Freedom Natural Knee Model Using Magnetic Resonance and Biplanar X-Ray Imaging During a Quasi-Static Lunge.

Musculoskeletal (MS) models can be used to study the muscle, ligament, and joint mechanics of natural knees. However, models that both capture subject-specific geometry and contain a detailed joint model do not currently exist. This study aims to first develop magnetic resonance image (MRI)-based subject-specific models with a detailed natural knee joint capable of simultaneously estimating in vivo ligament, muscle, tibiofemoral (TF), and patellofemoral (PF) joint contact forces and secondary joint kinematics. Then, to evaluate the models, the predicted secondary joint kinematics were compared to in vivo joint kinematics extracted from biplanar X-ray images (acquired using slot scanning technology) during a quasi-static lunge. To construct the models, bone, ligament, and cartilage structures were segmented from MRI scans of four subjects. The models were then used to simulate lunges based on motion capture and force place data. Accurate estimates of TF secondary joint kinematics and PF translations were found: translations were predicted with a mean difference (MD) and standard error (SE) of 2.13 ± 0.22 mm between all trials and measures, while rotations had a MD ± SE of 8.57 ± 0.63 deg. Ligament and contact forces were also reported. The presented modeling workflow and the resulting knee joint model have potential to aid in the understanding of subject-specific biomechanics and simulating the effects of surgical treatment and/or external devices on functional knee mechanics on an individual level.

The Effect of High Heel Shoes on Tibiofemoral and Patellofemoral joint Contact Forces and Muscle Forces

The Effect of High Heel Shoes on Tibiofemoral and Patellofemoral joint Contact Forces and Muscle Forces

Running Biomechanics in Individuals with Anterior Cruciate Ligament Reconstruction: A Systematic Review.

A return to running after anterior cruciate ligament reconstruction (ACL-R) is critical to the clinical success of any cutting and pivoting athlete who wishes to return to sport. Knowledge of specific alterations during running after ACL-R is required to optimise rehabilitation for improving outcomes and long-term disability. The objective of this systematic review was to summarise kinematic, kinetic and muscle activation data during running after ACL-R and the intrinsic factors (e.g. surgical technique and strength asymmetries) affecting running biomechanics. MEDLINE, EMBASE, SPORTDiscus and CINAHL databases were searched from inception to 10 December, 2018. The search identified studies comparing kinematic, kinetic or muscle activation data during running between the involved limb and contralateral or control limbs. Studies analysing the effect of intrinsic factors in the ACL-R group were also included. Risk of bias was assessed, qualitative and quantitative analyses performed, and levels of evidence determined. A total of 1993 papers were identified and 25 were included for analysis. Pooled analyses reported a deficit of knee flexion motion and internal knee extension moment, compared with both contralateral or control limbs, during the stance phase of running from 3months to 5years after ACL-R (strong evidence). Inconsistent results were found for both peak vertical ground reaction force and impact forces after ACL-R. Patellofemoral and tibiofemoral joint contact forces differed from both contralateral or control limbs up until at least 2.5years after ACL-R and moderate evidence indicated no difference for muscle activations during moderate speed running. Quadriceps and hamstring strength asymmetries, and knee function, but not surgical techniques, were likely to be associated with both knee kinematics and kinetics during running after ACL-R. After ACL-R, knee flexion motion and internal knee extension moment are the most affected variables and are consistently smaller in the injured limb during running when pooling evidence. Clinicians should be aware that these deficits do not appear to resolve with time and, thus, specific clinical interventions may be needed to reduce long-term disability. Registered in PROSPERO 2017, CRD42017077130.

Estimation of the Knee Adduction Moment and Joint Contact Force during Daily Living Activities Using Inertial Motion Capture.

Knee osteoarthritis is a major cause of pain and disability in the elderly population with many daily living activities being difficult to perform as a result of this disease. The present study aimed to estimate the knee adduction moment and tibiofemoral joint contact force during daily living activities using a musculoskeletal model with inertial motion capture derived kinematics in an elderly population. Eight elderly participants were instrumented with 17 inertial measurement units, as well as 53 opto-reflective markers affixed to anatomical landmarks. Participants performed stair ascent, stair descent, and sit-to-stand movements while both motion capture methods were synchronously recorded. A musculoskeletal model containing 39 degrees-of-freedom was used to estimate the knee adduction moment and tibiofemoral joint contact force. Strong to excellent Pearson correlation coefficients were found for the IMC-derived kinematics across the daily living tasks with root mean square errors (RMSE) between 3° and 7°. Furthermore, moderate to strong Pearson correlation coefficients were found in the knee adduction moment and tibiofemoral joint contact forces with RMSE between 0.006–0.014 body weight × body height and 0.4 to 1 body weights, respectively. These findings demonstrate that inertial motion capture may be used to estimate knee adduction moments and tibiofemoral contact forces with comparable accuracy to optical motion capture.

Skipping has lower knee joint contact forces and higher metabolic cost compared to running

BackgroundThe health benefits of running based exercise programs are plentiful however the high rate of injury in these programs often reduces or eliminates exercise participation. Skipping has shorter steps, reduced vertical ground reaction forces (GRFs), and lower knee extensor torques, compared to running forming the basis of the present hypothesis that skipping would have lower tibio-femoral and patello-femoral joint contact forces. Research questionThe purpose of this study was to compare knee contact forces between skipping and running at the same speed. We also compared metabolic cost of these two gaits to examine the idea that the larger vertical displacement in skipping is a primary factor in its previously reported high metabolic cost. MethodsThe study evaluated joint contact forces through musculoskeletal modeling with GRF and 3D kinematic data and metabolic cost using oxygen consumption data from 20 young, healthy, trained participants as they skipped and ran on an instrumented treadmill at 2.68 m/s. Results: Skipping, compared to running, had substantially lower tibio-femoral and patello-femoral joint contact forces and linear impulses on both per-step and per-kilometer (i.e. lower cumulative loads) bases and also 30% higher metabolic cost. The lower joint loads in skipping were directly associated with its shorter steps and the higher metabolic cost was directly associated to its larger vertical displacement through the stride. SignificanceAs joint loads may predispose individuals to running related injuries, skipping presents an attractive alternative exercise modality with additional increased aerobic benefits.