Kinetic and kinematic differences between deadlifts and goodmornings

Objectives: Anterior cruciate ligament reconstruction (ACLR) in adolescent patients is commonly performed utilizing hamstring (HT) or quadriceps (QT) tendon autografts. However, differences in jump landing biomechanics between these two graft types remains unclear. Understanding these differences can inform a graft-specific rehabilitation approach to improve jump landing biomechanics. The purpose of this study was to compare symmetry of jump landing biomechanics during drop vertical jump among ACLR patients with HT and QT grafts. Methods: This retrospective study included 53 adolescents who underwent unilateral ACLR (HT=23 patients; 12 female/11 male, QT=30 patients ; 16 female/14 male, mean age 16.1±1.3). Motion analysis data were collected during drop vertical jump between 7 to 9 months post-surgery. Drop vertical jump was captured using a 20 camera optical motion capture system (Vicon Motion Systems, Oxford, UK) synchronized with two Bertec force plates (Bertec Corporation, Columbus, OH). Anthropometrics, jump height, and ground reaction time were recorded. Variables of interest included maximum hip and knee flexion angles and maximum knee and hip flexion moments were calculated using the Dynamic Plug-in Gait Model. Energy absorption (average negative power) during landing and energy generation (average positive power) at maximal height vertical jumping were calculated by summing the joint work in all three planes and then divided by the time from initial contact to take off. The percentage of hip and knee power was derived as a ratio of the average power at the individual joint divided by the sum of the average power within the limb at the hip, knee, and ankle. Inter-limb asymmetry of each motion analysis variable was calculated as Bilateral Asymmetry Index (AI) between each limb (surgical versus non-surgical). A majority of participants completed the Pediatric International Knee Documentation Committee (Ped-IKDC) Subjective Knee Evaluation Form at the drop vertical measurement. Participants were grouped by graft type into HT (hamstring tendon) group and QT (quadricpes tendon) group, and participant characteristics were compared between two groups. Anthropometric information, jump height and ground reaction time were compared between HT and QT group by using unpaired t test. Motion analysis variables of surgical limb in HT group versus QT group, and non-surgical limb in HT group versus QT group were compared by using Mann-Whitney test. Differences in AI of biomechanical variables and Ped-IKDC score were also compared between two groups using Mann-Whitney test. Results: There were no differences in anthropometrics, jump height, ground contact time between two groups. Compared to HT group, QT group demonstrated 1) smaller maximum knee angles in surgical limb, 2) lower hip flexion moments in operated and non-operated limbs, 3) lower knee flexion moments in operated limbs, 4) lower negative power percentage and lower positive power percentage at the knee in operated limbs, and 5) higher positive power percentage at the hip in operated limbs (p<0.05). Asymmetries relative to the non-surgical limb observed in QT groups were greater compared to that in HT groups for 1) maximum knee and hip flexion angles, 2) knee flexion moments, 3) negative power percentage and positive power percentage at the knee. Conversely, asymmetries were smaller in the QT groups for negative power percentage and positive power percentage at the hip (p<0.05). There were no differences in Ped-IKDC score between two groups. Conclusions: Adolescent patients who underwent ACLR using QT graft demonstrated greater offloading at the knee and compensated with the hip in the surgical limb during jump landings, compared to those with HT grafts. Graft choice of QT or HT graft in ACLR may influence the knee biomechanical asymmetries. Further studies are required to determine how long these asymmetries persist. A graft-specific approach during rehabilitation may be needed to provide optimal return to sport and reinjury rate success between graft types.

Does knee external rotation differ according to frontal plane knee alignment and the presence of patellofemoral osteoarthritis after anterior cruciate ligament reconstruction?

Assessment of Kinematics and Electromyography Following Arthroscopic Single-Tendon Rotator Cuff Repair

To evaluate the effects of simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction on 1) the external knee adduction moment, 2) the external knee flexion and extension moments, and 3) the quadriceps, hamstrings, and gastrocnemius muscle activity during walking. Twenty-one patients with varus malalignment of the lower limb, medial compartment knee osteoarthritis, and concomitant anterior cruciate ligament (ACL) deficiency were tested before and 1 yr after undergoing simultaneous medial opening wedge high tibial osteotomy (HTO) and ACL reconstruction during a single operation. Three-dimensional kinetic and kinematic data were used to calculate external coronal and sagittal moments about the knee. EMG data from the quadriceps, hamstrings, and gastrocnemius were used to determine coactivation ratio and activation patterns. Neutral alignment and knee stability were achieved in all patients after surgery. The peak knee adduction moment decreased from 2.88 +/- 0.57 to 1.71 +/- 0.56%BW x Ht (P < 0.001). The early stance knee flexion moment decreased from 1.95 +/- 1.89 to 0.88 +/- 1.17%BW x Ht (P < 0.01). The late stance knee extension moment increased from 1.83 +/- 1.53 to 2.76 +/- 1.22%BW x Ht (P < 0.001). There were no significant differences in muscle coactivation or muscle activation patterns (P > 0.05). Improving lower limb alignment and knee stability significantly alters the coronal and the sagittal moments about the knee during walking, without apparent changes in muscle activation patterns.

Joint moment measurements represent an objective biomechanical parameter of knee joint load in knee osteoarthritis (KOA). Wearable sensors in combination with machine learning techniques may provide solutions to develop assistive devices in KOA patients to improve disease treatment and to minimize risk of non-functional overreaching (e.g., pain). The purpose of this study was to develop an artificial neural network (ANN) that estimates external knee flexion moments (KFM) and external knee adduction moments (KAM) during various locomotion tasks, based on data obtained by two wearable sensors. Thirteen participants were instrumented with two inertial measurement units (IMUs) located on the right thigh and shank. Participants performed six different locomotion tasks consisting of linear motions and motions with a change of direction, while IMU signals as well as full body kinematics and ground reaction forces were synchronously recorded. KFM and KAM were determined using a full body biomechanical model. An ANN was trained to estimate the KFM and KAM time series using the IMU signals as input. Evaluation of the ANN was done using a leave-one-subject-out cross-validation. Concordance of the ANN-estimated KFM and reference data was categorized for five tasks (walking straight, 90° walking turn, moderate running, 90° running turn and 45° cutting maneuver) as strong (r ≥ 0.69, rRMSE ≤ 23.1) and as moderate for fast running (r = 0.65 ± 0.43, rRMSE = 25.5 ± 7.0%). For all locomotion tasks, KAM yielded a lower concordance in comparison to the KFM, ranging from weak (r ≤ 0.21, rRMSE ≥ 33.8%) in cutting and fast running to strong (r = 0.71 ± 0.26, rRMSE = 22.3 ± 8.3%) for walking straight. Smallest mean difference of classical discrete load metrics was seen for KFM impulse, 10.6 ± 47.0%. The results demonstrate the feasibility of using only two IMUs to estimate KFM and KAM to a limited extent. This methodological step facilitates further work that should aim to improve the estimation accuracy to provide valuable biofeedback systems for KOA patients. Greater accuracy of effective implementation could be achieved by a participant- or task-specific ANN modeling.

Altered knee joint mechanics may be related to quadriceps muscle strength, time since surgery, and sex following anterior cruciate ligament reconstruction (ACLR). The aim of this study was to investigate the association between knee moments, with participant-related factors during stair navigation post-ACLR. Cross-sectional study. A total of 30 participants (14 women) with ACLR, on average 7.0 (SD 4.4) years postsurgery were tested during stair ascent and descent in a gait laboratory. Motion capture was conducted using a floor-embedded force plate and 11 infrared cameras. Quadriceps concentric and eccentric muscle strength was measured with an isokinetic dynamometer at 60°/s, and peak torques recorded. Multiple regression analyses were performed between external knee flexion and adduction moments, respectively, and quadriceps peak torque, sex, and time since ACLR. Higher concentric quadriceps strength and female sex accounted for 55.7% of the total variance for peak knee flexion moment during stair ascent (P < .001). None of the independent variables accounted for variance in knee adduction moment (P = .698). No significant associations were found for knee flexion and adduction moments during for stair descent. Higher quadriceps concentric strength and sex explains major variance in knee flexion moments during stair ascent. The strong association between muscle strength and external knee flexion moments during stair ascent indicate rehabilitation tailored for quadriceps may optimize knee mechanics, particularly for women.

Combining valgus knee brace and lateral foot wedges reduces external forces and moments in osteoarthritis patients

Background and Objectives: According to the well-established correlation between knee joint contact force and external knee adduction moment (KAM) during walking, many studies have focused on gait modifications that target changes in the frontal plane, such as foot progression and trunk inclination angles, to decrease KAM. However, recent research has highlighted the relationship between the external knee flexion moment (KFM) and knee joint contact force, highlighting the importance of considering both the KAM and KFM in gait modifications that highlight changes in the sagittal plane. Consequently, the current study aimed to investigate the effects of increasing knee joint flexion angle while walking on knee joint loading.Methods: This study was a cross-sectional study. 20 healthy older adults each performed two gait conditions - normal walking and walking with a 10-degree increase in the maximum flexion angle, with five trials conducted for each condition.Results: The results showed that increasing the flexion angle significantly reduced KAM. Specifically, the first peak KAM decreased from 0.59 ± 0.24 to 0.43 ± 0.26 N·m/kg·m (p < 0.001), and the second peak KAM from 0.57 ± 0.20 to 0.45 ± 0.25 N·m/kg·m (p = 0.002). Conversely, the peak KFM increased significantly from 1.5 ± 0.48 to 1.8 ± 0.51 N·m/kg·m (p < 0.001). Furthermore, gait modification involved a straightforward intervention-merely providing verbal instructions to slightly increase knee flexion angle-making it both feasible and practical for older adults at higher risk of developing osteoarthritis of the knee (knee OA).Conclusions: Ensuring sufficient knee joint flexion angle during the early stance phase may serve as an effective instructional strategy for reducing KAM. Given its simplicity and non-invasive nature, this intervention may have practical potential for use in clinical or community-based gait training programs for older adults at risk of knee OA. However, these findings should be interpreted with caution when generalized to patients with knee OA. Such individuals may have altered muscle activation, increased joint sensitivity, or limited range of motion, which could affect their response to gait modification. Future studies involving longitudinal follow-up or patient-centered outcomes such as pain, function, and adherence will be necessary to evaluate the long-term clinical applicability of this intervention.

Whether passive measures of isokinetic muscle strength deficits and knee laxity are related to the dynamic function of the anterior cruciate ligament-deficient knee remains unclear. Arthrometer measurements are not predictive of peak external knee flexion moment (net quadriceps muscle moment), isokinetic quadriceps muscle strength correlates with peak external knee flexion moment (net quadriceps muscle moment), and isokinetic hamstring muscle strength correlates with peak external knee extension moment (net flexor muscle moment). Cross-sectional study. Gait analysis was used to assess dynamic function during walking, jogging, and stair climbing in 44 subjects with unilateral anterior cruciate ligament deficiency and 44 control subjects. Passive knee laxity and isokinetic quadriceps and hamstring muscle strength were also measured. Arthrometer measurements did not correlate with peak external flexion or extension moments in any of the activities tested or with isokinetic quadriceps or hamstring muscle strength. Test subjects also had a significantly reduced peak external flexion moment during all three jogging activities and stair climbing compared with the control subjects and this was correlated with significantly reduced quadriceps muscle strength. Absolute knee laxity difference did not correlate with dynamic knee function as assessed by gait analysis and should not be used as a sole predictor for the outcome of treatment. Patients with greater than normal strength in the anterior cruciate ligament-deficient limb performed low- and high-stress activities in a more normal fashion than those with normal or less-than-normal strength.

BackgroundGait kinetics explains dynamics of gait deviations, which inform surgical and non-surgical clinical-decision-making to enhance walking performance of children with cerebral palsy. Kinetic gait profile of children with lesser crouch angle is known; however lower-extremity gait kinetics of ambulatory children at a further continuum of the spectrum with greater crouch angle is unclear. Therefore, present cross-sectional study evaluated influence of varying crouch angle on gait kinetics and walk distance.MethodFollowing ethical approval and signed informed consent of parents, 3-D gait of 33 ambulatory children with CP(10.4 year) and 31 age-matched typically-developing children was studied to compute the magnitude and timing of lower-extremity external net joint moments and power during stance phase. An average of 3gait trials walked bare-feet at self-selected pace was considered for analyses. Walk distance was measured with 2-min walk test. Typically developing children were classified as Group I, children with mild crouch-angle (mean knee flexion angle during stance)16.80and ≤ 250 were classified as Group II(n = 17), whereas children with severe crouch-angle i.e. 250 throughout stance phase were classified as Group III(n = 16). Three groups were compared with one-way-ANOVA(p ≤ 0.05). Bonferroni adjustment was made for post-hoc analyses (p ≤ 0.01).ResultsGait speed, cadence and 2-minute walk distance decreased from Group I to II to III(p ≤ 0.01). Hip flexion, extension and adduction; knee flexion and ankle dorsiflexion moments were significantly different between three groups(p ≤ 0.01)). Rise in crouch-angle was associated with an increase in peak hip flexion moment and increase in power generated at hip and decrease in power generated at knee and ankle (p ≤ 0.01). The timing of peak hip and knee moments during stance phase also differed across the 3 groups (p ≤ 0.01) indicating a delay in the occurrence of peak hip flexion-extension; abduction-adduction and knee flexion moment with a rise in crouch angle.ConclusionPresent findings inform lower-extremity joint kinetics during gait across the spectrum of mild to severe crouch angle with reference to typically-developing children. Precise knowledge of magnitude and pattern of net joint moments and power along with the timing of moments and decline in walking distance in children with severe crouch, can guide therapeutic interventions to restore the optimum dynamic lever arm function for improved walking performance.Trial registrationCTRI registration no. CTRI/22/12/048524/27/12/2022. Trial registry: CTRI/22/12. Trial registration number: 048524. Trial registration date: 27th December 2022.

The application of indoor exercise rehabilitation in diabetic patients Progress indoor exercise rehabilitation is an effective non-drug treatment method, which can be used to treat chronic disease management in diabetic patients. In recent years, with the continuous development and application of exercise rehabilitation technology, the application of indoor exercise rehabilitation in diabetic patients has also received extensive attention. This article will introduce the progress of the application of indoor exercise rehabilitation in diabetic patients, including exercise style, equipment and evaluation methods, as well as the impact of indoor exercise rehabilitation on glycemic control, physical function and mental health in diabetic patients. Through the introduction of this paper, we can understand the application status and future development trend of indoor exercise rehabilitation in the patients with diabetes, so as to provide more scientific and effective rehabilitation treatment for the patients with diabetes.

Background:Stiff landings with less knee flexion and high vertical ground-reaction forces have been shown to be associated with an increased risk of anterior cruciate ligament (ACL) injury. The literature on the association between other sagittal plane measures and the risk of ACL injuries with a prospective study design is lacking.Purpose:To investigate the relationship between selected sagittal plane hip, knee, and ankle biomechanics and the risk of ACL injury in young female team-sport athletes.Study Design:Case-control study; Level of evidence, 3.Methods:A total of 171 female basketball and floorball athletes (age range, 12-21 years) participated in a vertical drop jump test using 3-dimensional motion analysis. All new ACL injuries, as well as match and training exposure data, were recorded for 1 to 3 years. Biomechanical variables, including hip and ankle flexion at initial contact (IC), hip and ankle ranges of motion (ROMs), and peak external knee and hip flexion moments, were selected for analysis. Cox regression models were used to calculate hazard ratios (HRs) with 95% CIs. The combined sensitivity and specificity of significant test variables were assessed using a receiver operating characteristic (ROC) curve analysis.Results:A total of 15 noncontact ACL injuries were recorded during follow-up (0.2 injuries/1000 player-hours). Of the variables investigated, landing with less hip flexion ROM (HR for each 10° increase in hip ROM, 0.61 [95% CI, 0.38-0.99]; P < .05) and a greater knee flexion moment (HR for each 10-N·m increase in knee moment, 1.21 [95% CI, 1.04-1.40]; P = .01) was significantly associated with an increased risk of ACL injury. Hip flexion at IC, ankle flexion at IC, ankle flexion ROM, and peak external hip flexion moment were not significantly associated with the risk of ACL injury. ROC curve analysis for significant variables showed an area under the curve of 0.6, indicating a poor combined sensitivity and specificity of the test.Conclusion:Landing with less hip flexion ROM and a greater peak external knee flexion moment was associated with an increased risk of ACL injury in young female team-sport players. Studies with larger populations are needed to confirm these findings and to determine the role of ankle flexion ROM as a risk factor for ACL injury. Increasing knee and hip flexion ROMs to produce soft landings might reduce knee loading and risk of ACL injury in young female athletes.

BackgroundAcute and overuse knee injuries are common in sports involving jump-landing movements, especially in female athletes. More erect sagittal plane movement patterns are believed to increase injury risk. Whilst three-dimensional...

Study on the correlation between early three-dimensional gait analysis and clinical efficacy after robot-assisted total knee arthroplasty

BackgroundMechanical loading during exercise has been shown to promote tissue remodeling. Safe and accessible exercise may be beneficial to populations at risk of diminished bone and joint health. We examined the effect of drop height and instruction on knee loading during a drop-landing task and proposed a task that makes use of drop heights that may be appropriate for rehabilitation purposes and functional in daily life to examine transient knee joint loads.MethodsTwenty males (22.0 ± 2.8 years) performed drop landings from 22 cm (low) and 44 cm (high) heights, each under three instructions: “land naturally” (natural), “softly” (soft), and “stiffly” (stiff). Knee compression force and external flexion moment were estimated using three-dimensional inverse dynamics and normalized to body mass.ResultsPeak knee compression force was larger (p < 0.001) for high (17.8 ± 0.63 N/kg) than low (14.8 ± 0.61 N/kg) heights. There was an increase (p < 0.001) in the knee compression force across soft (11.8 ± 0.40 N/kg), natural (17.0 ± 0.62 N/kg), and stiff (20.2 ± 0.67 N/kg) instructions. Peak knee flexion moment in high-natural (2.12 ± 0.08 Nm/kg) was larger (p < 0.001) than in high-soft (1.88 ± 0.08 Nm/kg), but lower than in high-stiff (2.23 ± 0.08 Nm/kg). No differences in peak knee flexion moment were observed across instructions for the low height.ConclusionsWe propose a drop-landing task that creates a scalable increase in knee compression loading. The absence of increased knee flexion moment with drop from the low height, compared to high, suggests that individuals could perform the task without incremental risk of knee injury. This task could be used in future studies to examine the effect of acute bouts of mechanical loading on bone and cartilage metabolism.