scholarly journals The Impact Of Thigh And Shank Marker Quantity On Lower Extremity Kinematics Using A Constrained Model

2018 ◽  
Author(s):  
Annelise A Slater ◽  
Todd J. Hullfish ◽  
Josh R. Baxter
Keyword(s):  
Lower Extremity ◽  
Kinematic Model ◽  
Associate Editor ◽  
Human Motion ◽  
Joint Kinematics ◽  
Intellectual Content ◽  
Competing Interests ◽  
Musculoskeletal Models ◽  
Soft Tissue Artifact ◽  
The Impact

AbstractMusculoskeletal models are commonly used to quantify joint motions and loads during human motion. Constraining joint kinematics simplifies these models but the implications of the number of markers used during data acquisition remains unclear. The purpose of this study was to establish the effects of marker placement and quantity on kinematic fidelity when using a constrained-kinematic model. We hypothesized that a constrained-kinematic model would faithfully reproduce lower extremity kinematics regardless of the number of tracking markers removed from the thigh and shank. Healthy-young adults (N = 10) walked on a treadmill at slow, moderate, and fast speeds while skin-mounted markers were tracked using motion capture. Lower extremity kinematics were calculated for 256 combinations of leg and shank markers to establish the implications of marker placement and quantity on joint kinematics. Sagittal joint and hip coronal kinematics errors were smaller than documented errors caused by soft-tissue artifact, which tends to be approximately 5 degrees, when excluding thigh and shank markers. Joint angle and center kinematic errors negatively correlated with the number of markers included in the analyses (R2 > 0.97) and typically showed the greatest error reductions when two markers were included. Further, we demonstrated that a simplified marker set that included markers on the pelvis, lateral knee condyle, lateral malleolus, and shoes produced kinematics that strongly agreed with the traditional marker set. In conclusion, constrained-kinematic models are resilient to marker placement and quantity, which has implications on study design and post-processing workflows.Ethics Approval and Consent to Participate this study was approved by the Institutional Review Board at the University of Pennsylvania (#824466). Subjects provided written-informed consentConsent to Publish this submission does not contain any individual dataAvailability of Data and Materials the datasets analyzed in this study are available from the corresponding author on reasonable request.Competing Interests one author (JB) is an associate editor for BMC Musculoskeletal Disorders. None of the other authors have any competing interests.Funding no funding has been provided for this researchAuthors’ ContributionsAS, TH, and JB designed the experiment; AS and TH collected the data; AS and JB analyzed and interpreted the data; AS and JB drafted the manuscript; AS, TH, and JB revised the intellectual content of the manuscript; AS, TH, and JB approved the final version of the manuscript; and AS, TH, and JB agreed to be accountable for all aspects of the study.

scholarly journals The Effects of Repetitive Drop Jumps on Impact Phase Joint Kinematics and Kinetics

2011 ◽  
Vol 27 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Joshua T. Weinhandl ◽  
Jeremy D. Smith ◽  
Eric L. Dugan
Keyword(s):  
Energy Absorption ◽  
Plantar Flexion ◽  
Knee Extension ◽  
Joint Kinematics ◽  
Knee Extensors ◽  
Initial Contact ◽  
Drop Jumps ◽  
Impact Phase ◽  
The Impact ◽  
Kinematics And Kinetics

The purpose of the study was to investigate the effects of fatigue on lower extremity joint kinematics, and kinetics during repetitive drop jumps. Twelve recreationally active males (n= 6) and females (n= 6) (nine used for analysis) performed repetitive drop jumps until they could no longer reach 80% of their initial drop jump height. Kinematic and kinetic variables were assessed during the impact phase (100 ms) of all jumps. Fatigued landings were performed with increased knee extension, and ankle plantar flexion at initial contact, as well as increased ankle range of motion during the impact phase. Fatigue also resulted in increased peak ankle power absorption and increased energy absorption at the ankle. This was accompanied by an approximately equal reduction in energy absorption at the knee. While the knee extensors were the muscle group primarily responsible for absorbing the impact, individuals compensated for increased knee extension when fatigued by an increased use of the ankle plantar flexors to help absorb the forces during impact. Thus, as fatigue set in and individuals landed with more extended lower extremities, they adopted a landing strategy that shifted a greater burden to the ankle for absorbing the kinetic energy of the impact.

scholarly journals Role of Occupational Footwear and Prolonged Walking on Lower Extremity Muscle Activation during Maximal Exertions and Postural Stability Tasks

Biomechanics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 202-213
Author(s):  
Harish Chander ◽  
Sachini N. K. Kodithuwakku Arachchige ◽  
Alana J. Turner ◽  
Reuben F. Burch V ◽  
Adam C. Knight ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Postural Stability ◽  
Muscle Activation ◽  
Medial Gastrocnemius ◽  
Lower Extremity Muscle ◽  
Prolonged Duration ◽  
The Mean ◽  
The Impact

Background: Occupational footwear and a prolonged duration of walking have been previously reported to play a role in maintaining postural stability. The purpose of this paper was to analyze the impact of three types of occupational footwear: the steel-toed work boot (ST), the tactical work boot (TB), and the low-top work shoe (LT) on previously unreported lower extremity muscle activity during postural stability tasks. Methods: Electromyography (EMG) muscle activity was measured from four lower extremity muscles (vastus medialis (VM), medial hamstrings (MH), tibialis anterior (TA), and medial gastrocnemius (MG) during maximal voluntary isometric contractions (MVIC) and during a sensory organization test (SOT) every 30 min over a 4 h simulated workload while wearing ST, TB, and LT footwear. The mean MVIC and the mean and percentage MVIC during each SOT condition from each muscle was analyzed individually using a repeated measures ANOVA at an alpha level of 0.05. Results: Significant differences (p < 0.05) were found for maximal exertions, but this was limited to only the time main effect. No significant differences existed for EMG measures during the SOT. Conclusion: The findings suggest that occupational footwear type does not influence lower extremity muscle activity during both MVIC and SOT. Significantly lower muscle activity during maximal exertions over the course of the 4 h workload was evident, which can be attributed to localized muscular fatigue, but this was not sufficient to impact muscle activity during postural stability tasks.

Evaluation of CFRP Hole Quality in Low Frequency Vibration-Assisted Dry Drilling of CFRP/Ti Stacks

2018 ◽  
Author(s):  
Haojun Yang ◽  
Yan Chen ◽  
Jiuhua Xu
Keyword(s):  
Feed Rate ◽  
Kinematic Model ◽  
Mechanical Damage ◽  
Low Frequency ◽  
Spindle Speed ◽  
Hole Quality ◽  
Drilling Force ◽  
Low Frequency Vibration ◽  
The Impact ◽  
Conventional Drilling

Low frequency vibration assisted drilling (LFVAD) is regarded as one of the most promising process in CFRP/Ti stacks drilling. This work carries the investigation of the difference between conventional drilling and LFVAD based on kinematic model. The experiments are conducted under varied vibration amplitude to a specific feed rate, also under varying spindle speeds, feed rates when the ratio of amplitude to feed rate is fixed. Then the hole quality of CFRP is evaluated based on the analysis of drilling force, chip morphology, chip extraction. The results show that there is rarely no difference between conventional drilling and LFVAD in drilling mechanism when the drilling diameter is over 1 mm. Because the impact effect caused by drill vibration is already weak. It is found that the severe mechanical damage of the CFRP holes surface could be significantly reduced due to the fragmented chips obtained in vibration drilling. The maximum instantaneous feed rate combined with feed rate and amplitude plays a significant role in CFRP hole quality. Lower maximum instantaneous feed rate results in better hole wall quality and less entry delamination. Spindle speed has no visible influence on entry delamination, while higher spindle speed improves the hole surface quality due to the resin coating phenomenon.

In This Issue—The Impact of Birth Physiology on the Transition to Motherhood

2021 ◽  
Vol 30 (2) ◽  
pp. 59-61
Author(s):  
Judith A. Lothian
Keyword(s):  
Associate Editor ◽  
Transition To Motherhood ◽  
The Impact

In this column, the associate editor of The Journal of Perinatal Education discusses the impact of birth physiology on the transition to motherhood. The associate editor also describes the contents of this issue, which offer a broad range of resources, research, and inspiration for childbirth educators in their efforts to promote, support, and protect natural, safe, and healthy birth.

The impact of atrial fibrillation on one-year mortality in patients with severe lower extremity arterial disease

2021 ◽  
Author(s):  
Min-I Su ◽  
Cheng-Wei Liu
Keyword(s):  
Atrial Fibrillation ◽  
Lower Extremity ◽  
Oral Anticoagulants ◽  
Arterial Disease ◽  
Major Adverse Cardiovascular Events ◽  
Acute Limb Ischemia ◽  
Lower Extremity Arterial Disease ◽  
All Cause Mortality ◽  
One Year ◽  
The Impact

Abstract Backgroundand Aims: Atrial fibrillation (Afib) is associated with the incidence of lower extremity arterial disease (LEAD), but its effect on severe LEAD prognosis remains unclear. We investigated the association between Afib and clinical outcomes.Methods and ResultsWe retrospectively enrolled consecutive severe LEAD patients receiving percutaneous transluminal angioplasty between 2013/1/1 and 2018/12/31. Patients were divided by a history of any type of Afib and followed for at least one year. The primary outcome was all-cause mortality. Secondary outcomes were cardiac-related mortality, major adverse cardiovascular events (MACEs), and major adverse limb events (MALEs). The study included 222 patients aged 74 ± 11 years (54% male), and 12.6% had acute limb ischemia. The Afib group had significantly higher rates of all-cause mortality (42.9% vs. 20.1%, P = 0.014) and MACEs (32.1% vs. 14.4%, P = 0.028) than the non-Afib group. After adjustment for confounders, Afib was independently associated with all-cause mortality (adjusted HR: 2.153, 95% CI: 1.084–4.276, P = 0.029) and MACEs (adjusted HR: 2.338, 95% CI: 1.054–2.188, P = 0.037).ConclusionsAfib was significantly associated with increased risks of one-year all-cause mortality and MACEs in severe LEAD patients. Future studies should investigate whether oral anticoagulants benefit these patients.

scholarly journals The Impact of Novel Oral Anticoagulants on Outcomes of Patients Undergoing Lower Extremity Bypass

2020 ◽  
Vol 72 (1) ◽  
pp. e43-e44
Author(s):  
Carla C. Moreira ◽  
Lily Wang ◽  
Robert Patterson ◽  
Jeffrey M. Slaiby ◽  
Lars Stangenberg ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Oral Anticoagulants ◽  
Novel Oral Anticoagulants ◽  
The Impact

scholarly journals Durability of Smoking Cessation for Elective Lower Extremity Orthopaedic Surgery

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0039
Author(s):  
Danica H. Smith ◽  
Michael F. McTague ◽  
Michael J. Weaver ◽  
Jeremy T. Smith
Keyword(s):  
Smoking Cessation ◽  
Lower Extremity ◽  
Orthopaedic Surgery ◽  
Perioperative Complications ◽  
Smoking History ◽  
Secondary Outcome ◽  
Impaired Wound Healing ◽  
Patient Reported ◽  
The Impact

Category: General Health Introduction/Purpose: Smoking tobacco is a risk factor for impaired wound healing, infection, delayed fracture healing, and prolonged hospital stay. Smoking cessation prior to surgery has shown a 40% relative risk reduction in total perioperative complications. The primary purpose of this study is to evaluate the impact of preoperative smoking cessation on long-term smoking habits in patients undergoing elective lower extremity orthopaedic surgery. The secondary outcome is patient-reported effectiveness of smoking cessation method. Methods: A retrospective cohort study was performed by identifying all patients who were smokers that were required to quit and subsequently had a normal nicotine/cotinine serum test prior to lower extremity orthopaedic surgery. Attempts were made to contact all patients and administer a survey inquiring about demographics, medical history, smoking history, smoking cessation process, and current smoking status. Results: Of 36 eligible patients, 23 completed the survey. Eleven patients identified as current non-smokers (48%) at the time of survey follow-up (mean follow-up 55 months with a range of 12 to 88 months). Of these 11, 82% said they were very likely to continue to refrain from smoking. Twelve patients identified as current smokers at the time of survey, over half of whom ceased smoking for at least three months perioperatively. The reasons for resuming smoking were “stress” (45%), ”falling back into the habit” (37%), and due to “friends who smoke” (18%). The majority of smoking patients (92%) decreased the number of cigarettes they smoked regularly. The most effective smoking cessation techniques were ”cold turkey”, “non-nicotine medication”, and ”trans-dermal nicotine patches”. Conclusion: Elective surgery offers a unique opportunity for smoking cessation. Of 23 patients required to quit smoking prior to surgery, 48% maintained smoking cessation at least one year postoperatively. Of the 12 patients who relapsed, 55% stated that they did not resume smoking until at least three months postoperatively, suggesting that this particular period may be an important time for intensified smoking cessation counseling.

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