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.
Accurate identification of gait events is crucial to reliable gait analysis. Heel rise, a key event marking the transition from mid-stance to terminal stance, poses challenges in precise detection ...due to its gradual nature. This leads to variability in accuracy across studies utilizing diverse measuring techniques.
How do different HR detection methods compare when assessed against the underlying heel motion pattern and visual detection across varying speed, footwear conditions, and individuals?
Leveraging data from over 10,000 strides in diverse scenarios with 15 healthy subjects, we evaluated methods based on measurements from optical motion capture (OMC), force plates, and shank-mounted inertial measurement units (IMUs). The evaluation of these methods included an assessment of their precision and consistency with the heel marker's motion pattern and agreement with visually detected heel rise.
OMC-based heel rise detection methods, utilizing the heel marker's vertical acceleration and jerk, consistently identified the same point in the heel motion pattern, outperforming velocity-based methods and our new position-based method resembling traditional footswitch-based heel rise detection. Variability in velocity and position-based methods derives from subtle heel rise variations after mid-stance, exhibiting individual differences. Our proposed IMU-based methods show promise by closely matching OMC-based accuracy.
The results have significant implications for gait analysis, providing insights into heel rise event detection's complexities. Accurate HR identification is crucial for gait phase separation, and our findings, especially with the robust heel marker's jerk-based method, enhance precision and consistency across walking conditions. Moreover, our successful development and validation of IMU-based algorithm offer cost-effective and mobile alternative for HR detection, expanding their potential use in comprehensive gait analysis.
•We assess motion capture, force plate, and IMU data to identify the most precise heel rise detection method.•Subtle rising of the heel before the actual lift-off causes variability in heel rise detection.•Heel marker's acceleration and jerk-based methods are in high agreement with visual detection.•Novel IMU-based methods closely mirror the performance of acceleration and jerk-based methods.•The proposed methods improve heel rise detection accuracy for gait analysis.
To determine the agreement between 2-dimensional video analysis and subjective visual assessment by a physiotherapist in evaluating young athletes' knee control, and to determine the intrarater ...reliability and inter-rater reliability of the single-leg squat test.
Frontal plane knee control was assessed by a physiotherapist on a 3-point scale. Frontal plane projection angles were calculated from video images. To determine the intrarater reliability, a physiotherapist reassessed 60 subjects' performances from a video. For the inter-rater reliability, 20 subjects were assessed by both the physiotherapist and a nonexperienced tester. The study continued for 3 test years.
Research institute.
Three hundred and seventy-eight floorball, basketball, ice hockey, and volleyball players.
Knee control was assessed to be good, reduced, or poor.
Agreement between the video analysis and subjectively assessed frontal plane knee control. Intrarater reliability and inter-rater reliability.
There were statistically significant differences in the mean frontal plane knee angles between subjects rated as having "good," "reduced," or "poor" knee control. Intrarater reliability was fair for the assessments in the first year, moderate (dominant leg) and good (nondominant leg) for the second year, and very good (dominant leg) and good (nondominant leg) for the third year. Inter-rater reliability was fair/poor.
This study suggests that by using the subjective assessment of the single-leg squat task, it is possible to detect differences in frontal plane knee control in young team sport athletes. The assessment can be considered to be reliable for clinical use when performed by an experienced tester.
The purpose of this study was to evaluate the usability of a mobile phone with inbuilt thermal camera in wound imaging for medical purposes. Thermal imaging could help in evaluating wound healing and ...in assisting doctors in diagnose making. By using CAT S60 smart phone with an inbuilt Flir thermal camera, thermal pictures from skin wounds and lower limbs were taken from six people in order to find out if thermal imaging could help the treatment and diagnosis of a patient. Thermal images were taken in order to find and visualize temperature changes (being normally invisible) in skin damage areas including deep skin damages especially from limbs and extremities.
By using thermal imaging the beginning of treatment could be hastened and the monitoring of the state of a patient would be more efficient thus improving the prognosis of a patient. The thermal pictures taken from skin damages suggest that thermal imaging with CAT S60 smart phone can be used to improve nursing methods and may also help in diagnosis. Non-invasive thermal imaging may be a valuable asset and for its part hasten the beginning of treatment. The resolution and properties of CAT S60 smart phone was sufficient to detect skin damage temperature changes. This may suggest the usage of the CAT S60 smart in hospital, emergency ward and in home care services.
The purpose of this preliminary study was to examine, how thermal imaging could help in advancing nursing methods and offer some new usage targets of thermal imaging for the behoof of a patient. By ...using CAT S60 cellular phone with an inbuilt Flir thermal camera, thermal pictures were taken from voluntary subjects in order to find out if thermal imaging with CAT S60 phone could help in treatment of a patient. Thermal camera images were taken in order to find out temperature changes in whole body, limbs and extremities. By using thermal imaging in nursing the beginning of treatment could be hastened and the monitoring of the state of a patient would be more efficient thus improving the prognosis of a patient. The benefit of the method is, that it is non-invasive, cheap and easy to use (inside a cellular phone) thus being a clear advantage.
The results of different usage methods seen in thermal images suggest that thermal imaging with CAT S60 phone could be used to improve nursing methods and may also for its part to help in diagnosis. The present preliminary observations via thermal images showed, that the resolution of CAT S60 phone was sufficient to detect changes in human body temperature in home life. This may suggest the usage of the CAT S60 phone in home care services.
Accurate detection of gait events is crucial for gait analysis, enabling the assessment of gait patterns and abnormalities. Inertial measurement unit (IMU) sensors have gained traction for event ...detection, mainly focusing on initial contact (IC) and toe-off (TO) events. However, effective detection of other key events such as heel rise (HR), feet adjacent (FA), and tibia vertical (TBV) is essential for comprehensive gait analysis.
Can a novel IMU-based method accurately detect HR, TO, FA, and TBV events, and how does its performance compare with existing methods?
We developed and validated an IMU-based method using cumulative mediolateral shank angular velocity (CSAV) for event detection. A dataset of nearly 25,000 gait cycles from healthy adults walking at varying speeds and footwear conditions was used for validation. The method’s accuracy was assessed against force plate and motion capture data and compared with existing TO detection methods.
The CSAV method demonstrated high accuracy in detecting TO, FA, and TBV events and moderate accuracy in HR event detection. Comparisons with existing TO detection methods showcased superior performance. The method's stability across speed and shoe variations underscored its robustness.
This study introduces a highly accurate IMU-based method for detecting gait events needed to divide the gait cycle into seven phases. The effectiveness of the CSAV method in capturing essential events across different scenarios emphasizes its potential applications. Although HR event detection can be further improved, the precision of the CSAV method in TO, FA, and TBV detection advance the field. This study bridges a critical gap in IMU-based gait event detection by introducing a method for subdividing the swing phase into its subphases. Further research can focus on refining HR detection and expanding the method’s utility across diverse gait contexts, thereby enhancing its clinical and scientific significance.
•15 healthy participants, 24,519 steps, and 9 scenarios.•Using shank angular velocity, novel method detects gait events with precision.•Validated for initial contact, heel rise, toe-off, feet adjacent, and tibia vertical.•Bland-Altman plots, ICC scores show high agreement with gold standard techniques.
Background:
Few prospective studies have investigated the biomechanical risk factors of anterior cruciate ligament (ACL) injury.
Purpose:
To investigate the relationship between biomechanical ...characteristics of vertical drop jump (VDJ) performance and the risk of ACL injury in young female basketball and floorball players.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
At baseline, a total of 171 female basketball and floorball players (age range, 12-21 years) participated in a VDJ test using 3-dimensional motion analysis. The following biomechanical variables were analyzed: (1) knee valgus angle at initial contact (IC), (2) peak knee abduction moment, (3) knee flexion angle at IC, (4) peak knee flexion angle, (5) peak vertical ground-reaction force (vGRF), and (6) medial knee displacement. All new ACL injuries, as well as match and training exposure, were then recorded for 1 to 3 years. Cox regression models were used to calculate hazard ratios (HRs) and 95% CIs.
Results:
Fifteen new ACL injuries occurred during the study period (0.2 injuries/1000 player-hours). Of the 6 factors considered, lower peak knee flexion angle (HR for each 10° increase in knee flexion angle, 0.55; 95% CI, 0.34-0.88) and higher peak vGRF (HR for each 100-N increase in vGRF, 1.26; 95% CI, 1.09-1.45) were the only factors associated with increased risk of ACL injury. A receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.6 for peak knee flexion and 0.7 for vGRF, indicating a failed-to-fair combined sensitivity and specificity of the test.
Conclusions:
Stiff landings, with less knee flexion and greater vGRF, in a VDJ test were associated with increased risk of ACL injury among young female basketball and floorball players. However, although 2 factors (decreased peak knee flexion and increased vGRF) had significant associations with ACL injury risk, the ROC curve analyses revealed that these variables cannot be used for screening of athletes.
Although Nordic Walking (NW) is a fast growing form of exercise in Europe. This study aimed to determine how a supervised NW exercise program affects basic fitness and examine its application as a ...sports activity for supporting the health of elderly. Forty participants were randomly assigned to the NW group (NW: 66±4 years old) or the control group (CO: 68±4 years old). Functional measurements included the sit-and-reach test, timed-up and go test (TUG), knee extensor strength assessment, and incremental shuttle walking test (ISWT). Throughout the ISWT, the heart rate (HR) of each subject was monitored. Static balance was measured with a force platform under four test conditions: normal standing, with eyes open and closed, semi-tandem, and tandem standing with eyes open. These measurements were taken before and after the 8-week NW program. The NW group exercised 60–90 min/session, 3 times/wk. Results showed that NW training had positive effects on the TUG test, flexibility, and knee extensor strength (p < 0.05) assessments. In contrast, knee extensor strength was decreased in the CO group throughout the duration of the study (p < 0.05). The NW group walked with significantly lower HRs from level 1 (1.8 km/h) to 5 (4.3 km/h) after training (p < 0.05). However, there was no significant difference in HRs for the CO group during the ISWT. There were no significant changes between the groups in any of the four platform tests. In conclusion, the 8-week NW program either improved or maintained flexibility, leg strength, and cardiorespiratory endurance with no measurable changes in static balance.
Background
: Seven young patients were followed 52 weeks after intramedullary lengthening for limb length discrepancy (LLD). The mean LLD before surgery was 3.0 ± 1.1 cm and 1 year after surgery at ...the time of the nail‐removal it was 0.3 ± 0.3 cm.
Methods
: The plantar pressures and the ground reaction forces (GRF) were recorded simultaneously with electromyographic (EMG) activities at normal and fast walking speeds.
Results
: Bilateral comparison indicated that the uncorrected LLD resulted in asymmetrical gait patterns. The peak pressures were higher in the lateral heel and in the medial forefoot in the longer limb as compared to the shorter limb at normal walking speed. At fast walking speed, the peak pressures of the longer limb were higher in the forefoot area but lower in the central midfoot. One year after surgery, a clear improvement in the gait symmetry was observed compared to preoperative condition. Significantly, foot loading models were quite similar 52 weeks after surgery. However, during the follow‐up period of 52 weeks, the maximal isometric knee extensor torque still remained at lower levels on the operated side until week 52 postoperatively, but reached the same level with non‐operated side within 2 years.
Conclusions
: The improved walking symmetry obtained after surgical treatment may diminish possible pathologic loading of the lower extremity and may prevent the early appearance of arthritis in the lower extremities.
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