Decompression strain in parachute jumpmasters during simulated high-altitude missions: a special reference to preoxygenation strategies.

PURPOSE: Military parachute operations are often executed at high altitude, from an unpressurized aircraft compartment. Parachute jumpmasters (JM) are thus regularly exposed to 29,500 ft for 60 min. The aim was to investigate the decompression strain during a simulated JM mission at high altitude and to compare two strategies of preoxygenation, conducted either at sea-level or below 10,000 ft, during ascent to mission altitude. METHODS: Ten JM completed, on separate occasions, a 45-min preoxygenation either at sea-level (normobaric: N) or 8200ft (hypobaric: H), followed by exposure to 28,000 ft for 60 min, whilst laying supine and breathing 100% oxygen. At min 45 of the exposure to 28,000 ft, the JM performed 10 weighted squats. Decompression strain was determined from ultrasound assessment of venous gas emboli (VGE) during supine rest (5-min intervals), after three unloaded knee-bends (15-min intervals) and immediately following the weighted squats. The VGE were scored using a six-graded scale (0-5). RESULTS: In condition H, two JM experienced decompression sickness (DCS), whereas no DCS incidents were reported in condition N. The prevalence of VGE was higher in the H than the N condition, at rest [median(range), 3(0-4) vs 0(0-3); p = 0.017], after unloaded knee-bends [3(0-4) vs 0(0-3); p = 0.014] and after the 10 weighted squats [3(0-4) vs 0(0-3); p = 0.014]. VGE were detected earlier in the H (28 ± 20 min, p = 0.018) than the N condition (50 ± 19 min). CONCLUSIONS: A preoxygenation/altitude procedure commonly used by JM, with a 60-min exposure to 28,000 ft after pre-oxygenation for 45 min at 8200 ft is associated with high risk of DCS. The decompression strain can be reduced by preoxygenating at sea level.

Aerial maneuvering by plethodontid salamanders spanning an arboreality gradient.

Wandering salamanders (Aneides vagrans) inhabit the crowns of the world's tallest trees, taking refuge in epiphytic fern mats within these complex arboreal environments. These salamanders readily jump from the canopy when disturbed and maintain stable postures while falling via fine adjustments of the limbs and tail in lieu of dedicated aerodynamic control surfaces, thus reliably carrying out non-vertical descent. Here, we examined the aerial behavior and performance of A. vagrans and three other species of plethodontid salamander across a habitat gradient of arboreality by recording salamanders falling from short heights and moving within the jet of a vertical wind tunnel. Kinematic performance of aerial behavior in plethodontid salamanders was correlated with a gradient of arboreal habitats; moreover, salamanders from arboreal niches were more effective in slowing and redirecting descent compared with other salamanders. Aneides vagrans and the closely related Aneides lugubris consistently engaged in parachuting and gliding when falling; their trajectories were very steep, but were sufficiently angled to enable contact with either the home trunk or nearby branches during falls or jumps from great heights. Aerial maneuvering in arboreal salamanders is similar to that seen in other vertebrates capable of non-vertical and controlled descent, suggesting that the long limbs and active tail of these arboreal plethodontids (often cited as adaptations for climbing) may also contribute to parachuting and gliding when falling from trees. These aerial behaviors within the redwood canopy warrant further investigations into other canopy residents that lack conspicuous surfaces for aerodynamic control.

Analysis of the Objective Internal Load in Portuguese Skydivers in the First Jump of the Day.

The general objective of this study was to identify the variation in heart rate (HR) of Portuguese skydivers during 6 moments in their first jump of the day, bearing in mind the variable level of experience. Thirty-one Portuguese skydivers, 28 men and 3 women, aged between 19 and 62, participated in the study, 12 had A and B licenses (less experienced) and 19 had C and D licences (more experienced). The instrument used to record the heart rate of the skydivers at the different moments of their first jump of the day was the WIMU PRO. A repeated measures analysis of variance was used to analyse HR at different moments in the jump and its relation with the variables level of experience. Bonferroni multiple comparisons were performed to study the importance of the differences observed in HR at the different moments. The effect size was evaluated with partial eta squared. The results showed that average HR in this group of skydivers was 130 bpm, in the different moments of the jump. HR increases from the value recorded at rest until the moment of jumping from the plane and opening the parachute, reaching the highest average at that moment, then decreasing until contact with the ground. Comparing the variable, we found that the less experienced had higher HR than the more experienced at all moments during the jump. Statistically significant differences were found at the different moments of the jump, regarding HR (Max: p < 0.001, ƞ2p = 0.820; Min: p < 0.001, ƞ2p = 0.821; AVG: p < 0.001, ƞ2p = 0.834) Level of experience with jumping moment interaction, we only verified differences related to HR Min (p = 0.007, ƞ2p = 0.056),. With regard to experience, the identified differences were not statistically significant. Skydiving triggers an acute adaptive cardiovascular response which is reflected in the increase in the HR, between the moment of boarding the plane and the moment at which the parachute opens, thereafter decreasing until contact with the ground. The most experienced parachutists recorded the highest HR at the moment of landing and the least experienced at the moment of free fall.

A descriptive study of orthopaedic injuries due to parachute jumping in soldiers.

BACKGROUND: While parachute jumping, soldiers may suffer minor or life-threatening injuries in various parts of the body. Several trauma scoring systems assess the severity of such injuries. The primary goal of this study was to assess clinical characteristics and the severity of orthopaedic, musculoskeletal, and other injuries from military training-related parachute jumping using two trauma scoring systems (AIS and ISS). Our secondary goal was to assess whether there was an increase in injury rates with age. METHODS: In total, 185 military personnel between 19 and 51 years old who were injured as a result of daytime static parachute jumping during 44 months between January 2016 and August 2019 were included in the study. Demographic data; vital signs; the level of consciousness; the Glasgow Coma Scale; ISS trauma region classifications; anatomical injury sites; AIS and ISS scores; diagnoses; treatment methods; hospitalization status; and duration of hospital stay were examined descriptively. RESULTS: There were 184 male and one female participant. The most commonly injured body site was the foot (33.5%), and the most common diagnosis was soft tissue trauma (64.3%). The most commonly injured body site was the foot (33.5%), and the most common diagnosis was soft tissue trauma (64.3%). Regarding treatment methods, 51.4% received analgesic pills and cold pack application, 42.7% received a plaster splint, and 5.9% had orthopaedic surgery. The mean ISS score was 5.16 ± 3.92. The hospitalization rate was significantly higher for patients with a critical AIS score than those with a severe AIS score (p < 0.001). CONCLUSIONS: The use of trauma scoring systems to assess injury severity among patients admitted to an ED due to a parachute jumping injury may facilitate treatment selection. We found that AIS and ISS were useful in determining injury severity. Therefore, we recommend the use of trauma scoring systems for assessing the injury severity and the therapeutic approach, and we advocate for the use of the 17 anatomical regions we used in this study. We also found that with increasing age, the severity of injury could increase.

Traumatic injury patterns associated with static line parachuting.

OBJECTIVE: We investigated the incidence and injury patterns of acute parachuting injuries evaluated at a level II military facility during a 5-year period to compile medical information that may assist in improving the safety of parachuting. METHODS: A retrospective chart review of all parachuting injuries that presented to the Madigan Army Medical Center emergency department in Tacoma, Washington, during a 5-year period from February 2005 to June 2011. RESULTS: A total 110 patient charts met inclusion criteria. Lower extremity injuries made up 65% of total injuries, followed by 22% head injuries, 22% neck or back injuries, and 19% upper extremity injuries. One patient died in the emergency department of head injuries, and 1 patient was transferred for an open-book pelvic fracture. The most common phase of the jump in which to sustain injury was at landing. A total of 15 patients were admitted to the hospital. It is of note that some patients had combined injuries. The mechanism of injury documented in 96 of 110 (87%) patients and 10 of 15 (66%) admitted patients was a difficult landing. CONCLUSIONS: The rate of injury for each area of the body is within previously reported rates, with lower extremity injuries making up the largest category and leading to the majority of admissions. The most common time to sustain an injury was during landing, which represented a majority of both emergency room visits and hospitalizations.

Contemporary Outcomes and Patterns of Injury Associated With Parachuting Accidents.

BACKGROUND: Skydiving is an increasingly popular recreational activity in the United States and worldwide. While it is considered a high-risk sport, the United States Parachute Association reported a fatality of .28 per 100 000 jumps in 2022. Although mortality rates are low, the true rate of survivable injuries is unknown. Injuries requiring hospitalization are not uncommon and may be underreported in the literature. Anticipating these injuries and analyzing short-term outcomes following parachuting accidents would be useful for the development of mitigation strategies and to increase the safety of jumpers. METHODS: A retrospective cohort review of 126 consecutive patients presenting to a Level II Trauma Center after skydiving accidents between 2016 and 2023. Patient baseline characteristics, patterns of injury, surgical procedures, and in-hospital outcomes were reviewed. RESULTS: A total of 126 patients were included. One hundred and seventeen patients (93%) presented immediately following the accident, 65 (51.6%) were trauma activations, and 14 (11.1%) patients experienced loss of consciousness. Fractures of the lower extremity occurred in 57 (45%), fractures of the spine 48 (38%), upper extremity 13 (10%), pelvis 11 (9%). Of the spinal injuries, 10 injuries occurred in the cervical spine, 16 thoracic, 22 lumbar, 5 sacral, and 3 coccygeal spine. Eleven patients (9%) suffered multilevel spine injuries. Mean injury severity score was 7 (range 0-75). A third of patients required at least 1 surgical procedure (n = 43, 34%). Median length stay was 2 days (IQR 1, 5). Of patients who survived to our trauma center, there were two mortalities, both due to catastrophic intracranial hemorrhage. DISCUSSION: Although the 30-day mortality rate for patient who presented to our trauma center is low, it can bear significant risks including major injury. The most common injuries were lower extremity and spinal in origin with a third of patients overall requiring at least one operation.

Fatalities in wingsuit BASE jumping.

OBJECTIVE: To analyze fatality data associated with wingsuit use in an international case series of fixed-object sport parachuting (BASE jumping) to identify incident and injury mechanisms and to form a basis for potential prevention measures and future safety recommendations. METHODS: A descriptive epidemiological study was performed of fatal injury events occurring in wingsuit BASE jumping. Fatalities (n = 180) were sequentially analyzed assessing human, equipment, and environmental factors from 1981 to 2011. Main outcome measures included descriptions of typical fatal incident and injury mechanisms. RESULTS: Of the 180 fatal events, 39 (22%) were related to use of wingsuits; 38 (97%) launched from cliffs and 1 (3%) from a building. Of the 39 fatalities, 19 (49%) were caused from cliff strikes, 18 (46%) from ground impact, and 1 (3%) from a building strike. Thirty-eight (97%) of the fatalities were male. During 2002 to 2007 there was a total of 61 BASE jumping deaths, 10 (16%) of which were related to the use of wingsuits, whereas during 2008 to 2011 there was a total 59 fatal events, of which 29 (49%) were related to the use of wingsuits. Seventeen fatalities (39%) were attributed to wingsuit path miscalculation. In the first 8 months of 2013, 17 of 19 (90%) fatalities were wingsuit related. Most fatalities occurred between April and October, reflecting a seasonal increase in activity in the northern hemisphere summer. CONCLUSIONS: Wingsuit-related BASE jump fatalities appear to be increasing as wingsuit BASE jumping increases in popularity. Most fatalities are attributed to cliff or ground impact, and are mostly the result of flying path miscalculation.

Bilateral Pneumothoraces in a Tandem Parachuting Passenger Without Traumatic Impact: A Case Report.

In parachuting, orthopedic and head injuries are well-documented risks associated with the parachute deployment and landing phases. Thoracic injuries have only been seen on rare occasion in conjunction with direct impact trauma. In this report, we detail a case of a young, healthy, tandem skydiving passenger who suffered bilateral pneumothoraces with delayed symptom onset, with no identifiable injury during the jump or landing. Exploring the forces of the parachute "opening shock," we suggest a plausible compressive mechanism for this novel presentation, as well as briefly discuss the options for diagnosis and conservative management of pneumothorax in the operational context. While this is an exceedingly rare event, pneumothorax should be considered in patients complaining of thoracic symptoms following a skydive.

Finite element analysis of shank and ankle with different boot collar heights in parachuting landing on inversion ground surface.

This study aimed to the biomechanics of the foot-ankle-shank complex with different boots collar heights in parachuting landing on inversion ground surface. A finite element model including tibia, fibula, ankle, foot and parachuting boot was developed. Three collar heights (low, medium, high) of the parachuting boot were simulated. Von-Mises stress, ankle inversion angle, ligament force and bone displacement were analyzed. Compared with that of the high and low collar heights, boots with medium collar height produced the lowest peak stress on the tibia and the articular cartilage of the subtalar joint. In addition, the medium collar height can better control the ankle inversion and minimize the tensile forces on the lateral ankle ligaments.

To parachute or not.

This editorial was prompted by a criticism of our inability to identify all existing local oncologic human resources prior to the initiation of a women's cancer care platform in the Democratic Republic of the Congo. We discuss the act of parachuting, i.e., intermittent visits by investigators from high-income countries to low-and middle-income countries, its dichotomization (positive and negative), role in bilateral collaborations between high-income and low-and middle-income countries, contributing etiologies and potential harms. Lastly, we highlight our use of parachuting to successfully transfer breast and cervical cancer diagnostic and surgical skills to healthcare providers in a low-income African nation, while simultaneously building clinical infrastructure for women's cancers. We conclude with recommendations that pertain to the development of better research ecosystems in Africa.

Finite element analysis of lumbar spine with different backpack positions in parachuting landing.

The purpose of this study was to investigate the lumbar spine stress with different backpack positions in parachuting landing using a finite element model of lumbar vertebra 1-5. The backpack gravity center was set at three positions (posterior-high (case PH), posterior-low (case PL), and anterior-low (case AL)) respectively. In results, the peak Von-Mises stresses of the matrix, nucleus, fibers, endplate and ligament in case AL were 2.765 MPa, 0.534 MPa, 6.561 MPa, 4.045 MPa and 1.790 MPa respectively, lower than those in case PL (6.913 MPa, 1.316 MPa, 20.716 MPa, 10.917 MPa and 5.147 MPa respectively) and case PH (7.328 MPa, 1.394 MPa, 22.147 MPa, 11.617 MPa and 5.464 MPa respectively). In conclusion, setting the gravity center of backpack at anterior-low position would reduce lumbar spine stress and reduce lumbar spine injuries.

Protection by Ankle Brace for Lower-Extremity Joints in Half-Squat Parachuting Landing With a Backpack.

Half-squat parachuting landing is a kind of activity with high impact force. Injuries on lower-extremity joints are common in half-squat parachuting landing and would be increased with a backpack. An ankle brace was used to prevent ankle injuries in landing. However, few quantitative studies reported about the protection of an ankle brace for lower-extremity joints in half-squat parachuting landing with a backpack. This study focused on evaluating the protective effects of an ankle brace in half-squat parachuting landing with a backpack. Seven male participants landed from 120 cm with a backpack and an ankle brace. Each participant performed three landing trials on every experimental condition. Kinetics and kinematics of the hip, knee, and ankle were analyzed. It was found that the ankle brace did not significantly affect the ground reaction force with backpack but increased the ground reaction force from 14.7 ± 2.0 bodyweight to 16.2 ± 1.9 bodyweight (p = 0.017) without the backpack. The ankle brace significantly (p < 0.05) decreased the angular displacement, angular velocity, and angular acceleration of the ankle both without and with the backpack. In conclusion, the ankle brace could restrict ankle motion and significantly increase ground reaction force without the backpack. However, the ankle brace did not significantly influence ground reaction force and still restricted ankle motion with the backpack. Therefore, the ankle brace was more effective in half-squat parachuting landing with the backpack than no-backpack landing.

Abuse, Toxicology and the Resurgence of Propylhexedrine: A Case Report and Review of Literature.

Propylhexedrine, the active ingredient in over-the-counter nasal decongestants, carries significant abuse potential for users seeking psychostimulant effects. Historically, propylhexedrine was perceived to have a good safety profile resulting in endorsement of it replacing the highly abused amphetamine sulfate as the active ingredient in nasal decongestants in 1949. While much of the published literature concerning its psychoactive potential comes from the 1970s and 1980s, we have encountered several recent cases of toxidrome secondary to its abuse. Awareness of the hazards associated with this pharmaceutical should be of interest to physicians of all specialties who are likely to encounter such cases, as well and legislators interested in exerting regulatory control. Here we review all existing literature concerning this pharmaceutical compound.

Kinematics and kinetics of lower-extremity joints in parachuting landing with backpack and knee brace.

Injuries on lower-extremity joints were caused by high impact force in parachuting landing. Knee brace was used to protect knee by restraining motion of knee. Backpack was necessary in parachuting landing and would increase lower-extremity joints injuries. This study aimed to analyze kinematics and kinetics of hip, knee and ankle for investigating multi-joint protection of knee brace for those joints in parachuting landing with backpack. Seven participants landed from 120 cm height. Kinematics and kinetics of hip, knee and ankle were analyzed. It was found that without backpack knee brace decreased angular displacements of hip (12.0%), knee (10.3%) and ankle (18.6%) on sagittal plane and angular velocities of hip (11.9%), knee (6.6%) and ankle (20.9%) on sagittal plane. With backpack, knee brace decreased angular displacement (5.5%) and angular velocity of knee (6.2%) on sagittal plane, but did not significantly influence those of hip and ankle on sagittal plane. Ground reaction force, joint moments and joint energy absorptions were not significantly influenced with knee brace. In conclusion, in parachuting landing without backpack, knee brace could provide multi-joint protection for hip, knee and ankle. In parachuting landing with backpack, knee brace could still protect knee, but could not protect hip and ankle.

Epidemiology and injury patterns of aerial sports in Switzerland.

BACKGROUND: Airborne sports have become more popular in recent years. The number of accidents has increased linearly as athletes take increasingly greater risks to experience the adventurous spirit of this kind of sports. AIM: To investigate the variety of injuries in airborne sport accidents, as well as which acute treatment these patients receive, both before and after admission to a level-one-trauma center. METHODS: We performed a retrospective chart analysis at a major level-one-trauma center in Switzerland for 235-patients who were admitted following airborne sports injuries between 2010 and 2017. Patients' demographic data, injury patterns, emergency primary care procedures and intra-hospital care were recorded. RESULTS: Overall, 718-injuries in 235-patients were identified; the spine was the most commonly affected region with 46.5% of injuries (n = 334/718) in 143-patients. In 69-patients (15.5%), the (non-spine) thorax was affected, followed by the lower and upper extremity, pelvis, head/face and abdominal injuries. Eleven-patients had to be intubated at the trauma site. Three patients were resuscitated after onset of pulseless-electrical-activity. Two-patients died in the resuscitation room. In 116-cases, surgery was indicated including 55-emergency surgeries. Another 19 patients (8.1%) were transferred to the intensive care unit. CONCLUSION: Paragliders are most commonly affected, although the highest injury severities were identified for Building, Antenna, Span and Earth-jumping athletes. First responders, treating physicians and pilots should be aware of the risk for potentially serious and life-threatening injury with an in-hospital mortality of 0.9%.

Two new species of treefrog (Pelodrydidae: Litoria) from southern New Guinea elucidated by DNA barcoding.

New Guinea is home to the world's most diverse insular frog biota, but only a small number of taxa have been included in genetically informed assessments of species diversity. Here we describe two new species of New Guinea treefrog in the genus Litoria that were first flagged during assessments of genetic diversity (DNA barcoding) and are currently only known from the holotypes. Litoria pterodactyla sp. nov. is a large green species in the Litoria graminea species complex from hill forests in Western Province, Papua New Guinea and is the third member of this group known from south of the Central Cordillera. Litoria vivissimia sp. nov. is a small, spike-nosed species from mid-montane forests on the Central Cordillera. It is morphologically very similar to Litoria pronimia, but occurs nearly 1000 m higher than any known locality for that species. More extensive genetically informed assessment of diversity in New Guinea frogs seems certain to reveal many more as-yet-unrecognised taxa in complexes of morphologically similar species.

Suicide in parachuting: A case report and review of the literature.

Skydiving fatalities are mostly accidental and the result of human errors. However, suicides may be greatly underreported in skydivers. We present the case of a young civilian skydiver who committed suicide by jumping from an altitude of 4000m without activating his chutes. Witnesses reported that the victim had remained in a freefall position until ground impact. Besides an extensive blunt trauma, the autopsy showed an antero-posterior flattening of the body with symmetrical abrasions on its front, which were consistent with a high-energy impact on the ground in a "belly-down" position. Police investigation revealed that the victim had expressed suicidal thoughts in text messages before jumping from the airplane, and examination of his equipment showed that he had disabled the security system allowing the reserve chute to be automatically deployed at low altitude. To the best of our knowledge, this is the first case of suicide of a skydiver that has been described in the scientific literature. A suicidal intent should be assumed in skydiving fatalities involving jumpers with operable but un-activated parachutes on their back. This case highlights the importance of a thorough forensic investigation in such circumstances to ascertain the manner of death.

Parachuting psychoactive substances: Pharmacokinetic clues for harm reduction.

BACKGROUND: Parachuting, also called bombing, is a way to ingest psychoactive substances wrapped into cigarette paper, toilet paper, etc. There is little data describing parachuting in terms of substances use, context of use and, most importantly, the motivations for using such wrappers, although some authors hypothesized that parachute could be used for pharmacokinetic reason. However, inconsistently, some authors report that parachutes are used for sustained-release whereas others report that users are looking for an immediate effect. RESEARCH DESIGN AND METHODS: Considering parachute as a "home-made" dosage form, we have applied the dissolution testing to characterize the dissolution performance of a substance wrapped into a parachute and to characterize whether a parachute represents an immediate-release form or not. RESULTS: This in-vitro study provides the first pharmacokinetic data for drugs wrapped in parachutes. It shows that parachute acts as sustained-release form when made with a cigarette paper wrapper, but as immediate release form in the presence of alcohol or if wrapped with toilet paper. CONCLUSIONS: An important message to harm reduction is that users must be aware that a parachute can have unexpected pharmacokinetics and have to avoid taking another parachute in the absence of an immediate-effect to avoid overdose.

Skydiving and the risk of cervical disc herniation.

The skydiving/parachuting sport which has recently gained popularity is also known for its accidents and injuries. However, there are a few studies related to its occupational ergonomic risks and occupational musculoskeletal diseases. It has been reported that the sudden hyperextension of the neck during the parachute opening, so called opening shock results in neck pain. It has been found that the jumpers are subjected to an average deceleration of 3-5 times the earth's gravitational acceleration (3-5 G) during parachute opening shock. It is considered that the spinal cord is destabilized by the impact of this force. This study presents the occupational cervical disc herniation occurring in the case of a subject who has been working as a skydiving/parachuting instructor for 25 years, and the ergonomic risks specific to the sports of skydiving. There is a requirement for systematic and representative studies related to the administrative measures to be taken in order to prevent the occupational diseases that may occur in the case of skydivers, the personal protective equipment to be used, and the employee. Int J Occup Med Environ Health 2018;31(2):243-249.

Retrospective Study of Injuries in Military Parachuting.

BACKGROUND: This paper analyses the rate and patterns of parachuting injuries at the Sultans Oman Parachute Unit (SOPRA) in Oman. METHODS: Data on 150 patients referred to Rustaq Regional Referral Hospital was collected and analysed. The injuries were defined as severe (fractures, dislocation, head trauma) or minor (contusion, bruises, sprains). RESULT: The rate of severe injuries was 9 % and ankle fractures were the commonest. The minor injury rate was 13.5%. The injury rate increased in relation to age (p < 0.001). The type and possible mechanisms of injury are discussed with the recommendation for reducing the injury rates. CONCLUSION: We conclude that our data compares favourably with other studies except for higher incidence of severe injuries.