Frontal Plane Hip Motion Research Articles

Validity of an artificial intelligence, human pose estimation model for measuring single-leg squat kinematics

Few studies have investigated the validity of 2D pose estimation models to evaluate kinematics throughout a motion and none have included adolescents. Adolescent athletes completed single-leg squats while 3D kinematic data and 2D sagittal and frontal plane videos were recorded. Sagittal and frontal plane joint motion throughout the single-leg squats and angles at peak knee flexion were compared among 2D pose estimation, 3D motion analysis, and traditional 2D motion analysis techniques. Statistical parametric mapping compared waveforms while Pearson’s correlation compared the relationships of joint angles at peak knee flexion among techniques, respectively. We observed significant waveform differences between 2D pose estimation and 3D motion analysis at the beginning and end of the squat for sagittal plane hip and knee motion, for most of the squat for frontal plane hip motion, and throughout the entire squat for sagittal plane ankle motion and frontal plane pelvic motion. We observed moderate-to-strong relationships (r = 0.68-0.94) for sagittal plane joint angles between 2D pose estimation and 3D techniques. We observed fair correlations (r = 0.53-0.54) for frontal plane pelvic and hip joint angles between 2D pose estimation and 3D motion analysis. We observed poor relationships for the frontal plane knee angle between 3D motion analysis with 2D pose estimation (r = 0.20) and traditional 2D motion analysis (r = 0.05), respectively, but observed a strong relationship (r = 0.95) between the 2D techniques. 2D pose estimation is a valid alternative to 3D motion analysis and traditional 2D motion analysis for evaluating most sagittal and frontal plane angles during a single-leg squatting task.

2282 Targeted eccentric motor control to improve locomotion after incomplete spinal cord injury

OBJECTIVES/SPECIFIC AIMS: Incomplete spinal cord injury typically results in life-long disability, often in the form of profound loss of locomotion capability. Individuals who have experienced incomplete spinal cord injury exhibit persistent eccentric motor deficits, which are particularly prevalent in the weight acceptance phase of gait and emphasized in sagittal plane knee motion and frontal plane hip motion. METHODS/STUDY POPULATION: Motion analysis can capture the kinematic and joint-level deficits of these individuals, but it is impossible to directly calculate the contributions of individual muscles to weight acceptance due to the complexity of the musculoskeletal system. Instead, those muscle contributions must be simulated in order to approximate muscle power during locomotion. RESULTS/ANTICIPATED RESULTS: The traditional method for driving these simulations with electromyography readings is unavailable for individuals who have neuromuscular deficits (e.g., spasticity or paralysis), due to the need to generate reliable maximum voluntary isometric contractions for baseline purposes. Instead, this research develops a novel method for using resting electromyography data to drive musculoskeletal simulations using a muscle activation threshold paradigm. DISCUSSION/SIGNIFICANCE OF IMPACT: The simulation results of this method more closely resemble experimental results, but further simulation refinement is needed to fully capture the true muscle activity.

Gait Kinematics in Individuals with Acute and Chronic Patellofemoral Pain.

This study aimed to identify the discriminating kinematic gait characteristics between individuals with acute and chronic patellofemoral pain (PFP) and healthy controls. Ninety-eight runners with PFP (39 male, 59 female) and 98 healthy control runners (38 male, 60 female) ran on a treadmill at a self-selected speed while three-dimensional lower limb kinematic data were collected. Runners with PFP were split into acute (n = 25) and chronic (n = 73) subgroups on the basis of whether they had been experiencing pain for less or greater than 3 months, respectively. Principal component analysis and linear discriminant analysis were used to determine the combination of kinematic gait characteristics that optimally separated individuals with acute PFP and chronic PFP and healthy controls. Compared with controls, both the acute and chronic PFP subgroups exhibited greater knee flexion across stance and greater ankle dorsiflexion during early stance. The acute PFP subgroup demonstrated greater transverse plane hip motion across stance compared with healthy controls. In contrast, the chronic PFP subgroup demonstrated greater frontal plane hip motion, greater knee abduction, and reduced ankle eversion/greater ankle inversion across stance when compared with healthy controls. This study identified characteristics that discriminated between individuals with acute and chronic PFP when compared with healthy controls. Certain discriminating characteristics were shared between both the acute and chronic subgroups when compared with healthy controls, whereas others were specific to the duration of PFP.

Comparison Of Post-ACLR Kinematics Between Landings Of A Drop Vertical Jump

The drop vertical jump (DVJ) task is used to assess functional recovery after an anterior cruciate ligament reconstruction (ACLR). A DVJ has two distinct phases, and while the 1st landing is more commonly analyzed, the 2nd landing follows a maximal jump and may better represent higher-risk sport situations. Comparing the kinematics of each landing in subjects after an ACLR would provide insights into the specific qualities of each landing to inform clinical examination and future research. PURPOSE: To compare hip and knee kinematics of the reconstructed limb between the 1st and 2nd landing of a DVJ in patients after ACLR. METHODS: 22 subjects (10 F, age 20.6±5 y, H 1.7±0.1 m, M 71±12 kg) 6 months post-ACLR performed a DVJ. Subjects were asked to step off of a 30.5 cm box, land (1st landing), maximally jump, and land once more (2nd landing) during an instrumented data collection. Visual 3D was used to calculate hip and knee kinematics at initial contact. Paired sample t-tests were used to compare between landings. RESULTS: The ACLR limb demonstrated less knee flexion but greater knee abduction and internal rotation angles during the 2nd landing (Table 1). The hip exhibited less flexion and internal rotation motion. No differences were observed in frontal plane hip motion. CONCLUSION: The 1st and 2nd landings of a DVJ require distinct kinematics of the ACLR limb. Less knee flexion combined with greater knee abduction and internal rotation of the ACLR limb during the 2nd landing suggests that this landing better detects abnormal mechanics associated with subsequent injury risk. Thus, the 2nd landing could warrant additional study to identify patients who may be at greater risk for re-injury after ACLR.Table 1: Kinematic variables at foot strike during 1st and 2nd landings of a drop vertical jump

Frontal and transverse plane hip kinematics and gluteus maximus recruitment correlate with frontal plane knee kinematics during single-leg squat tests in women

BackgroundHip muscle dysfunction may be associated with knee valgus that contributes to problems like patellofemoral pain syndrome. The purpose of this study was to (1) compare knee and hip kinematics and hip muscle strength and recruitment between “good” and “poor” performers on a single-leg squat test developed to assess hip muscle dysfunction and (2) examine relationships between hip muscle strength, recruitment and frontal plane knee kinematics to see which variables correlated with knee valgus during the test. MethodsForty-one active women classified via visual rating as “good” or “poor” performers on the test participated. Participants completed 5-repetition single-leg squat tests. Isometric hip extension and abduction strength, gluteus maximus and gluteus medius recruitment, and 3-dimensional hip and knee kinematics during the test were compared between groups and examined for their association with frontal plane knee motion. Findings“Poor” performers completed the test with more hip adduction (mean difference=7.6°) and flexion (mean difference=6.3°) than “good” performers. No differences in knee kinematics, hip strength or hip muscle recruitment occurred. However, the secondary findings indicated that increased medial hip rotation (partial r=0.94) and adduction (partial r=0.42) and decreased gluteus maximus recruitment (partial r=0.35) correlated with increased knee valgus. InterpretationWhereas hip muscle function and knee kinematics did not differ between groups as we'd hypothesized, frontal plane knee motion correlated with transverse and frontal plane hip motions and with gluteus maximus recruitment. Gluteus maximus recruitment may modulate frontal plane knee kinematics during single-leg squats.

Comfort and midfoot mobility rather than orthosis hardness or contouring influence their immediate effects on lower limb function in patients with anterior knee pain

BackgroundDespite evidence for use of foot orthoses in the treatment of anterior knee pain, there is a paucity of research into their mechanisms of action. This study (i) determined the immediate lower limb kinematics and muscle activity adaptations, and (ii) evaluated the effect of individual's comfort and foot mobility. MethodsForty individuals diagnosed with anterior knee pain were measured for lower limb kinematics and electromyographic activity (via surface electrodes) while they jogged in three prefabricated contoured orthoses (hard, medium and soft) and a soft-flat orthosis. Subjects ranked orthoses in order of comfort. FindingsSoft orthoses were more comfortable. No immediate adaptations in kinematics and electromyographic activity were observed when orthoses were added to shoes. There were few effects of perceived comfort and foot mobility, one being a significant interaction in frontal plane hip motion (Pillai's V=0.089, P=0.031) with the least comfortable orthosis producing the greatest relative adduction in those with mobile feet (0.54° (standard deviation 0.87)). Other main effects were a significant increase in vastus lateralis activity when wearing the least comfortable orthosis (6.94%, P=0.007) and a delay in offset of medial gastrocnemius in individuals with less mobile feet (1.51%, P=0.045). InterpretationIt is becoming apparent that it is important to use more comfortable foot orthoses in a condition like anterior knee pain, where there is an associated increased hip adduction and vastus lateralis activity with least comfortable orthoses. Future research is needed to determine adaptations after ongoing wearing of orthoses.

Gender and Foot Orthotic Device Effect on Frontal Plane Hip Motion During Landing From a Vertical Jump

Excessive hip motion has been linked to lower extremity pathology. Foot orthoses are commonly used to control motion within lower extremity joints when lower extremity pathology and dysfunction are present. Few studies have investigated the effect of foot orthoses on hip angular kinematics during functional activities. Eighteen females and 18 males performed a vertical jump with and without a prefabricated foot orthoses to determine the biomechanical effect of foot orthoses on hip kinematics when landing from a jump. Data collection included three-dimensional motion analysis of the lower extremity. Paired t tests were performed to determine if differences existed within genders with and without foot orthoses. At the hip joint, there was significantly less hip adduction motion in the foot orthoses condition as compared with the no foot orthoses condition in females (p < .05). There were no differences between foot orthoses conditions in males. Females appear to have a different proximal response to foot orthoses when landing from a forward jump than males.

A 5&amp;deg; medial wedge reduces frontal but not saggital plane motion during jump landing in highly trained women athletes

Lower extremity mechanics during landing have been linked to traumatic and nontraumatic knee injuries, particularly in women's athletics. The effects of efforts to mitigate these risks have not been fully elucidated. We previously reported that a 5° medial wedge reduced ankle eversion and knee valgus. In the present report we further investigated the effect of a 5° medial wedge inserted in the shoes of female athletes on frontal plane hip motion, as well as ankle, knee, hip, and trunk saggital plane motion during a jump landing task. Kinematic data were obtained from 10 intercollegiate female athletes during jump landings from a 31 cm platform with and without a 5° medial wedge. Hip adduction was reduced 1.98° (95% CI 0.97-2.99°) by the medial wedge but saggital plane motions were unaffected. A 5° medial wedge reduces frontal plane motion and takes the knee away from a position associated with anterior cruciate ligament injury and patellofemoral pain syndrome. Although frontal plane motion was not captured it is unlikely to have increased in a bilateral landing task. Thus, it is likely that greater muscle forces were generated in these highly trained athletes to dissipate ground reaction forces when a medial wedge was in place. Additional investigation in younger and lesser trained athletes is warranted to assess the impact of orthotic devices on knee joint mechanics.

Calculation of Cycling Mechanics Symmetry in Competitive Cyclists

Cycling mechanics symmetry has been extensively studied given the importance to injury prevention and performance. The definition of symmetry, however, varies within the literature and limits valid comparisons. PURPOSE: To determine and compare cycling mechanics symmetry within and between three calculated methods. METHODS: Thirty one competitive cyclists (Age: 34.5 ±9.8 years; Height: 1.77 ± 0.11 m; Mass: 76.3 ± 11.1 kg) cycled untethered on a high speed treadmill at 25.8 km · hr-1 and a 2% incline. Kinematic and pedal force data were collected with a 3D motion analysis system and custom designed pedals. Total sagittal and frontal plane motion of the hip and knee, sagittal plane ankle motion, maximum power and recovery phase effective forces were calculated. The dependent variables were analyzed for Right - Left (RL), Dominant - Non-Dominant (DN), and Larger Total Kinematic Excursion - Smaller Total Kinematic Excursion (GP) methods. A symmetry score was calculated for each dependent variable as the within-method percent difference and compared between the three methods. A priori statistical significance was set at p < 0.05 for all analyses. RESULTS: Frontal plane hip (R: 14.2 ±3.8°, L: 16.1 ± 5.0°) and knee (R: 19.8 ± 9.6°, L: 25.6 ± 13.8°) motion were asymmetrical for the RL comparisons. Power (D: 353.0 ± 65.4 N, N: 311.3 ± 62.5 N) and recovery (D: 44.6 ± 18.3 N, N: 34.6 ± 13.8 N) phase effective forces were asymmetrical for the DN comparisons. Frontal plane hip (G: 16.3 ± 4.8°, P: 14.0 ± 4.0°) and knee (G: 26.6 ± 12.7°, P: 18.8 ± 10.3°) motion and sagittal plane ankle motion (G: 36.1 ± 12.5°, P: 27.4 ± 9.6°) were asymmetrical for the GP comparisons. RL - GP symmetry scores varied for frontal plane hip (RL: −16.4 ± 30.6%, GP: 10.5 ±22.6%) and knee (RL: −54.0 ± 107.6%, GP: 17.9 ± 47.0%) motion and sagittal plane ankle motion (RL: −8.3 ± 44.2%, GP: 20.9 ± 22.1%). DN - GP symmetry scores varied for frontal plane hip motion (DN: −11.6 ± 33.7%, GP: 10.5 ± 22.6%), sagittal plane ankle motion (DN: −4.2 ± 42.2%, GP: 20.9 ± 22.1%), and power phase effective force (DN: 11.5 ±8.2%, GP: −2.8 ± 16.6%). RL - DN symmetry scores varied for power phase effective force (RL: −1.8 ± 16.6%, DN: 11.5 ±8.2%). CONCLUSIONS: Identification of cycling mechanics symmetry is method-specific and a consensus is necessary with regard to denning symmetry for valid data comparisons.