The effect of a startle-based warning, age, sex, and secondary task on takeover actions in critical autonomous driving scenarios

Introduction: In highly autonomous driving scenarios, it is critical to identify strategies to accelerate reaction times since drivers may take too long to take over control of the vehicle. Previous studies reported that an Acoustic Startling Pre-Stimulus (ASPS, i.e., a loud warning preceding an action) accelerated reaction times in simple ankle flexion exercises.

Methods: In this study, we examined if an ASPS warning leads to shorter takeover reaction times in a sled-simulated evasive swerving maneuver. Twenty-eight participants (seven male adults, seven male teenagers, seven female adults, and seven female teenagers) were instructed to align a marker on the steering wheel with a marker on a lateral post as fast as they could as soon as the lateral sled perturbation (0.75 g) started. Four conditions were examined: with and without an ASPS (105 dB, played 250 ms before sled perturbation for 40 ms), and with and without a secondary task (i.e., texting). A catch trial (ASPS only) was used to minimize anticipation. Human kinematics were captured with an 8-camera 3D motion capture system.

Results: Results showed that the drivers’ hands lifted towards the steering wheel more quickly with the ASPS (169 ± 55 ms) than without (194 ± 46 ms; p = 0.01), and that adult drivers touched the steering wheel quicker with the ASPS (435 ± 54 ms) than without (470 ± 33 ms; p = 0.01). Similar findings were not observed for the teen drivers. Additionally, female drivers were found to lift their hands towards the steering wheel faster than male drivers (166 ± 58 ms vs. 199 ± 36 ms; p = 0.009).

Discussion: Our findings suggest that the ASPS may be beneficial to accelerate driver reaction times during the initiation of a correction maneuver, and that autonomous vehicle warnings may need to be tailored to the age and sex of the driver.

Head excursions of rearward-facing child restraint systems in rear impacts

OBJECTIVE

The aim of the current study was to quantify the head excursions of pediatric anthropomorphic test devices (ATDs) seated in rearward-facing child restraint system (CRS) models during rear impact sled tests and compare to roof heights of vehicles in the current fleet to assess the possibility of head contact against the vehicle roof.

METHODS

Head excursions of ATDs seated in rearward-facing CRS models were analyzed from high-speed video data from 14 rear impact sled tests across two different series. Tests were conducted in rigidized vehicle seats from recent model year vehicles. Rearward-facing infant and convertible CRS models were tested with a variety of pediatric ATDs aged 12 months to 6 years in a variety of installation conditions (e.g., lower anchors or seat belt, anti-rotation features, etc). Maximum ATD head excursions in plane of the seatback were compared to previously measured roof heights of 87 different vehicles.

RESULTS

The roof heights in all sedan seating positions (n = 58) and SUV/CUV/minivan seating positions (n = 60) were greater than the largest maximum ATD head excursions in plane of the seatback (792 mm). Head contact was possible in two of the pickup trucks which had roof heights of 730 and 775 mm. In all, 98% of vehicle seating positions measured in this study would accommodate all of the maximum ATD head excursions in plane of the seatback without contact.

CONCLUSIONS

The risk of head contact against the vehicle interior roof appears low as maximum ATD head excursions in plane of the seatback were typically not great enough to reach the rooflines of the vehicles in the sample. Head contact appears possible in pickup trucks, where the window/roofline is directly behind the head restraint.

Characterizing neck and spinal response in booster seated reclined children in frontal impacts

OBJECTIVE

Belt-positioning booster seats (BPB) and pre-pretensioner (PPT) belts may be effective in preventing injuries from submarining and head excursion in reclined children. It is unknown if injuries at the neck and spine could still occur. This study's goal is to characterize neck and spine responses in reclined children with and without the BPB and the PPT.

METHODS

Eleven frontal impact sled tests were performed (56 kph) with the Large Omnidirectional Child (LODC) dummy on a production vehicle seat. A 3-point simulated seat-integrated-belt was used with a load-limiter (∼4.5 kN). Testing was conducted with and without the BPB with the seatback at ∼25°, ∼45° and repeated once. One test was conducted at ∼60° with the BPB. 100 mm of belt-slack was removed to simulate PPT in two 45° BPB tests and the BPB 60° test. The LODC peak thoracic spine accelerations and angular rotations, and peak neck and lumbar force/moment loads were compared between conditions.

RESULTS

Neck shear forces were the highest in the 60° BPB & PPT (-1.9 kN) and 45° noBPB (-1.3 kN) than all other BPB conditions (-0.5 to -0.8 kN). The highest peak neck moments were found in the 45° noBPB (-40.5 N-m), and in the 60° BPB & PPT (-34.2 N-m) conditions compared to all others (-20.8 to -27.9 N-m.). The 60° BPB and PPT condition demonstrated thoracic forward rotation similar to the 25° noBPB condition (25° noBPB -24.8 to -35.0 deg, 60° BPB&PPT -27.5 to -43.2 deg.). Thoracic spine peak resultant accelerations (T1, T6, T12) were higher in the 25° and 45° noBPB conditions (53 g to 71 g) and in the 60° BPB & PPT (T6: 61.8 g) compared to all other BPB conditions (48.4 g to 53.1 g). The lumbar peak shear forces and moments were the highest in the 45° noBPB (4.9 kN, -296 N-m) and the 60° BPB & PPT condition (1.7 kN, -146 N-m).

CONCLUSION

These findings show similarities in neck, spine, and lumbar responses between the 60° reclined condition with BPB and PPT and the 25° and 45° conditions without the same countermeasures. This study highlights the need for future restraint developments to protect moderate and severe reclined BPB-seated child occupants.

Trends in Practice Among Shoulder Specialists in the Management of Frozen Shoulder: A Consensus Survey

Background:

The management of frozen shoulder (FS) differs depending on experience level and variation between scientific guidelines and actual practice.

Purpose:

To determine the current trends and practices in the management of FS among shoulder specialists and compare them with senior shoulder specialists.

Study Design:

Consensus statement.

Methods:

A team of 15 senior shoulder specialists (faculty group) prepared a questionnaire comprising 26 questions regarding the definition, terminology, clinical signs, investigations, management, and prognosis of FS. The questionnaire was mailed to all the registered shoulder specialists of Shoulder and Elbow Society, India (SESI) (specialist group; n = 230), as well as to the faculty group (n = 15). The responses of the 2 groups were compared, and levels of consensus were determined: strong (>75%), broad (60%-74.9%), inconclusive (40%-59.9%), or disagreement (<40%).

Result:

Overall, 142 of the 230 participants in the specialist group and all 15 participants in the faculty group responded to the survey. Both groups strongly agreed that plain radiographs are required to rule out a secondary cause of FS, routine magnetic resonance imaging is not indicated to confirm FS, nonsteroidal anti-inflammatory drugs should be administered at bedtime, steroid injection (triamcinolone or methylprednisolone) is the next best option if analgesics fail to provide pain relief, passive physical therapy should be avoided in the freezing phase, <10% of patients would require any surgical intervention, and patients with diabetes and thyroid dysfunction tend to fare poorly. There was broad agreement that routine thyroid dysfunction screening is unnecessary for women, a single 40-mg steroid injection via intra-articular route is preferred, and arthroscopic capsular release (ACR) results in a better outcome than manipulation under anesthesia (MUA). Agreement was inconclusive regarding the use of combined random blood sugar (RBS) and glycosylated hemoglobin versus lone RBS to screen for diabetes in patients with FS, preference of ACR versus MUA to treat resistant FS, and the timing of surgical intervention. There was disagreement over the most appropriate term for FS, the preferred physical therapy modality for pain relief, the most important movement restriction for early diagnosis of FS, and complications seen after MUA.

Conclusion:

This survey summarized the trend in prevalent practices regarding FS among the shoulder specialists and senior shoulder surgeons of SESI.

Interactions between rearward-facing child restraint systems and the front row seatback in frontal impact sled tests

OBJECTIVE

Some child restraint system (CRS) manufacturers specify a minimum distance between the CRS and the seatback, whereas others require that the CRS may contact the seatback but cannot be "braced"; however, few studies have investigated these interactions. Therefore, the aim was to investigate the interactions between the front row seat and rearward-facing CRS models with and without a support leg during frontal crashes.

METHODS

Sled tests using the FMVSS 213 frontal crash pulse were performed with the Q1.5 and Q3 anthropomorphic test devices (ATDs) seated in rearward-facing infant and convertible CRS models, respectively. A front row vehicle seat was in front of the test bench in three track positions: brace, touch and gap. For the touch condition, the front row seat was translated aftward until the seatback contacted the CRS. For the brace condition, the front row seat was translated 20 mm aftward. For the gap condition, the front row seat was translated 50 mm forward. Each condition was tested with and without the support leg of the CRS.

RESULTS

The tests with a support leg were associated with significantly (p = 0.007) lower resultant linear head acceleration 3 ms clip compared to the tests without a support leg, but the reduction of head injury criterion 15 ms (HIC15) was not significant (p = 0.057). The Q1.5 ATD in the rearward-facing infant CRS with a support leg had the lowest injury metrics for the touch and gap conditions, whereas the Q3 in the rearward-facing convertible CRS had the lowest head injury metrics for the brace condition.

CONCLUSIONS

The use of a support leg provided a clear benefit in terms of reducing head injury metrics for the Q1.5 in the rearward-facing infant CRS, especially for the touch and gap conditions. The rearward-facing convertible CRS in the current study appears to benefit from being braced against the front row seat. However, further tests are required to allow further statistical comparisons and determine if these preliminary findings extend to other rearward-facing CRS models.

COVID 19 Care Call-in Helpline. A Report from India

A COVID 19 call helpline was established by a noted TV channel along with a group of consultant doctors at the height of the second wave COVID 19 pandemic in India. It helped the general public to understand dos and donts as well as long term implications. We retrospectively analysed the questions asked to get a feel of the misunderstandings and perceptions within the general public. Many quereies related to the vaccination drive.

Prophylaxis for preventing venous thromboembolism in knee arthroscopy and soft tissue reconstruction: consensus statements from an international panel of experts

PURPOSE

There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines like ones for trauma surgery and arthroplasty do not exist and the published literature is limited to case reports with a few society guidelines. Given this lack of consensus, we conducted a modified Delphi questionnaire of international experts to provide recommendations on this topic.

METHODS

The consensus statements were generated using an anonymised 3 round modified Delphi questionnaire, sent to an international panel of 38 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics with measures like mode, median and box plots. Feedback was provided to all panelists based on responses from the previous rounds to help generate the consensus.

RESULTS

Six consensus statements were generated after the three rounds of Delphi. Patient factors, prolonged surgery duration and family history of thrombogenic events emerged as the main points to be taken into consideration for prophylaxis.

CONCLUSION

It was established through this study, that there exists a select group of patients undergoing arthroscopic surgery that justify the usage of VTE prophylaxis. The expert responses to most of the questions in different scenarios favoured usage of VTE prophylaxis based on patient factors like advanced age, past history of VTE, smoking, oral contraceptive use etc. LEVEL OF EVIDENCE: Level V.

Management Guidelines for Infection After ACL Reconstruction: Expert Opinion Statement Based on the Modified Delphi Survey of Indian Arthroscopy Surgeons

AIM

Infection after anterior cruciate ligament (ACL) reconstruction, though rare, is a potentially devastating complication and the evidence-based recommendation on the various topics in its management is limited. The purpose of this study was to develop recommendations for the prevention and management of infections in ACL reconstruction surgery by performing a structured expert consensus survey using Delphi methodology.

MATERIALS AND METHODS

22 topics of relevance in the prevention and management of infection following ACL reconstruction were chosen from an extensive literature review. 30 panelists were requested to respond to a three-round survey, with feedback, to develop a consensus statement on the topics.

RESULTS

Consensus statements could be prepared in eleven out of twenty-two topics including: the graft is retained at the first arthroscopic debridement, the graft is removed when repeated debridement are needed, and revision ACL reconstruction is needed only if the patient develops instability. Concurrence could be obtained in the topics including: longer duration of antibiotics is needed in immunocompromised patients, soaking graft in antibiotic solution reduces infection risk, and knee swelling without warmth does not suggest infection.

CONCLUSIONS

A proper skin preparation, a longer course of antibiotics in immunocompromised patients, and soaking the graft in antibiotics reduces the risk of infection. In case of infection, a healthy-looking graft must be retained at the first debridement and if the graft must be removed, revision ACL reconstruction is advised only if the patient develops instability.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00363-z.

Analysis of Kinematic Response of Pediatric Occupants Seated in Naturalistic Positions in Simulated Frontal Small Offset Impacts: With and Without Automatic Emergency Braking

Naturalistic driving studies have shown that pediatric occupants do not assume ideal seating positions in real-world scenarios. Current vehicle assessment programs and child restraint system (CRS) sled tests, such as FMVSS No. 213, do not account for a wide range of seating postures that are typically observed during real-world trips. Therefore, this study aims to analyze the kinematic and kinetic response of a pediatric human body model in various naturalistic seating positions in booster seats when subjected to a frontal offset impact in a full-vehicle environment, with and without the application of pre-crash automatic emergency braking (AEB). A 6YO (seated on a lowback and highback booster) and a 10YO (seated in no-CRS and on a lowback booster) PIPER pediatric human body model's response was explored in a reference, and two most commonly observed seating postures: forward-leaning and forward-inboard-leaning. The vehicle environment with a side-curtain airbag (SCAB) was subjected to a small offset barrier impact (25% overlap at 40MPH), with and without the application of a pre-crash automatic emergency braking (AEB). 24 conditions were simulated using finite element analysis. Cases with a pre-crash AEB resulted in relatively lower kinematic and kinetic values due to the occupant being in a more flexed position before impact compared to without-AEB cases, coupled with the increased ride-down effect due to AEB. Moreover, different seating postures resulted in substantially different kinematics and kinetics, the injury metrics crossing the injury assessment reference values in some cases. Therefore, to design a passive safety standard test for pediatric occupants, it is important to consider the possible postural changes that may occur.

Pseudarthrosis of the surgical neck of humerus treated by buttressing with a medial cortico-cancellous graft

BACKGROUND

Pseudarthrosis of surgical neck of humerus is uncommon condition. Different methods of improving the stability of fixation have been described, including impaling the shaft into the head, placing a tension suture through the rotator cuff, or using an intramedullary cortical graft. We report our results of cortico-cancellous strut graft medially to counter the varus force, in conjunction with a fixed-angle implant on the lateral side.

MATERIALS AND METHODS

We used this technique in seven cases of pseudarthrosis of surgical neck of the humerus. There were four women and three men, ranging in age from 22 to 65 years. All were treated with a tricortical medial buttress bone graft and fixed-angle fixation device on the lateral side. A locking proximal humerus plate (Synthes) was used in six cases, and a bent reconstruction plate (Synthes) was applied in one case. The one in which reconstruction plate was applied was operated before the advent of locking plates. The limb was immobilized in 30° of abduction over a cushion for 6 weeks, followed by a sling for another 6 weeks.

RESULTS

The followup varied from 18 to 96 months. All our cases healed within mean 5.1 months (range 4-6 months). There was one case of avascular necrosis. All cases had useful function of shoulder.

CONCLUSION

The medial buttressing by strut graft with external fixation by laterally placed fixed angle plate is successful to achieve fracture union in pseudarthrosis of surgical neck of humerus.

Factors Affecting Implant Failure in Fracture of the Shaft of Femur

17 cases of implant failure of fracture of shaft of femur were studied. All cases were young adults less than40 years of age. 15 were males. 16 of 17 cases sustained their initial injury in road - traffic accidents. Platefailures were detected earlier than those of nails as nails kept on providing splintage to an otherwise ununitedfracture. 10 of 17 cases were treated by interlocking nailing during the resurgery. Cortico-cancellous bonegrafting was done in 9 of 17 cases as per merit of each case. Follow-up ranged from 6 months to 2 years. 15of 17 cases went on to sound union after the second operation.The wrong choice of implant, implants improperly applied and bone grafting not done as recommended(i.e. technical errors) is the major cause of implant failure. Nails with diameter more than 10 mm should beused as far as possible. Early detection and resurgery for K-nail failure should be done to prevent greateramount of shortening. Wherever plating is done, instead of attempting anatomic reduction and devascularisingthe bone, biological method of fixation should be used.Key Words: Implant Failure, Shaft of Femur, Fracture.

Angiomyoma of the knee joint: value of magnetic resonance imaging

A case of angiomyoma as an unusual cause of knee pain is presented and the usefulness of magnetic resonance imaging in such a situation is discussed.