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Biomedical subjects

P Gunnar Brolinson

Publications and source records attributed to P Gunnar Brolinson.

10 recordsLinked to original sources
PubMed2006

Analysis of linear head accelerations from collegiate football impacts.

Sports-related concussions result in 300,000 brain injuries in the United States each year. We conducted a study utilizing an in-helmet system that measures and records linear head accelerations to analyze head impacts in collegiate football. The Head Impact Telemetry (HIT) System is an in-helmet system with six spring-mounted accelerometers and an antenna that transmits data via radio frequency to a sideline receiver and laptop computer system. A total of 11,604 head impacts were recorded from the Virginia Tech football team throughout the 2003 and 2004 football seasons during 22 games and 62 practices from a total of 52 players. Although the incidence of injury data are limited, this study presents an extremely large data set from human head impacts that provides valuable insight into the lower limits of head acceleration that cause mild traumatic brain injuries.

Acceleration↗
PubMed2006

Biomechanical response of the lumbar spine in dynamic compression.

The purpose of this study was to investigate the biomechanical properties of the human lumbar spine subjected to dynamic compression. A series of six experiments using the lumbar spines from four human cadavers was performed. The first two tests utilized the entire lumbar spine while the remaining four tests used lumbar functional joints to separate the differences in stability. A high rate material testing machine was used to produce the dynamic compression at a displacement rate of 1 m/s. Custom mounting plates were developed to ensure proper anatomical position of the lumbar spine sections. Both tests with the whole lumbar spines resulted in compression fractures at T12 due to combined axial loads of 5009 N and 5911 N and bending moments of 237 Nm and 165 Nm respectively. These failures occurred as the spine behaved in first order buckling which resulted in concentrated loading and bending of the anterior aspects of the vertebral bodies. All tests with functional units resulted in endplate fractures and recorded substantially higher axial loads between 11,203 N and 13,065 N and substantially lower bending moments between 47 Nm and 88 Nm. The results indicate that the mechanical stability of the lumbar spine is critical component in relation to the tolerable compressive loads.

Biomechanical Phenomena↗
PubMed2005

Analysis of real-time head accelerations in collegiate football players.

OBJECTIVE: To measure and analyze head accelerations during American collegiate football practices and games. METHODS: A newly developed in-helmet 6-accelerometer system that transmits data via radio frequency to a sideline receiver and laptop computer system was implemented. From the data transfer of these accelerometer traces, the sideline staff has real-time data including the head acceleration, the head injury criteria value, the severity index value, and the impact location. Data are presented for instrumented players for the entire 2003 football season, including practices and games. SETTING: American collegiate football. SUBJECTS: Thirty-eight players from Virginia Tech's varsity football team. MAIN OUTCOME MEASUREMENTS: Accelerations and pathomechanics of head impacts. RESULTS: : A total of 3312 impacts were recorded over 35 practices and 10 games for 38 players. The average peak head acceleration, Gadd Severity Index, and Head Injury Criteria were 32 g +/- 25 g, 36 g +/- 91 g, and 26 g +/- 64 g, respectively. One concussive event was observed with a peak acceleration of 81 g, a 267 Gadd Severity Index, and 200 Head Injury Criteria. Because the concussion was not reported until the day after of the event, a retrospective diagnosis based on his history and clinical evaluation suggested a mild concussion. CONCLUSIONS: The primary finding of this study is that the helmet-mounted accelerometer system proved effective at collecting thousands of head impact events and providing contemporaneous head impact parameters that can be integrated with existing clinical evaluation techniques.

Acceleration↗
PubMed2005

Current concepts in the evaluation and management of stress fractures.

Although new technologies aid in making a rapid diagnosis and help predict clinical course of treatment, the diagnosis of stress fractures remains dependent on a high index of suspicion. Management of stress fractures involves clinical knowledge of those stress fractures that are prone to complication. The identification of predisposing factors to stress injury should be addressed. These include proper nutrition, hormonal balance, and correcting biomechanical deficits and training errors. Comprehensive evaluation and treatment is essential in facilitating recovery from stress fracture. Several new and more aggressive prevention and treatment strategies have been reported. The maintenance of cardiovascular fitness throughout the recovery process remains a key to the fastest return to full participation.

Biomechanical Phenomena↗
PubMed2004

Upper extremity interaction with a helicopter side airbag: injury criteria for dynamic hyperextension of the female elbow joint.

This paper describes a three part analysis to characterize the interaction between the female upper extremity and a helicopter cockpit side airbag system and to develop dynamic hyperextension injury criteria for the female elbow joint. Part I involved a series of 10 experiments with an original Army Black Hawk helicopter side airbag. A 5(th) percentile female Hybrid III instrumented upper extremity was used to demonstrate side airbag upper extremity loading. Two out of the 10 tests resulted in high elbow bending moments of 128 Nm and 144 Nm. Part II included dynamic hyperextension tests on 24 female cadaver elbow joints. The energy source was a drop tower utilizing a three-point bending configuration to apply elbow bending moments matching the previously conducted side airbag tests. Post-test necropsy showed that 16 of the 24 elbow joint tests resulted in injuries. Injury severity ranged from minor cartilage damage to more moderate joint dislocations and severe transverse fractures of the distal humerus. Peak elbow bending moments ranged from 42.4 Nm to 146.3 Nm. Peak bending moment proved to be a significant indicator of any elbow injury (p = 0.02) as well as elbow joint dislocation (p = 0.01). Logistic regression analyses were used to develop single and multiple variate injury risk functions. Using peak moment data for the entire test population, a 50% risk of obtaining any elbow injury was found at 56 Nm while a 50% risk of sustaining an elbow joint dislocation was found at 93 Nm for the female population. These results indicate that the peak elbow bending moments achieved in Part I are associated with a greater than 90% risk for elbow injury. Subsequently, the airbag was re-designed in an effort to mitigate this as well as the other upper extremity injury risks. Part III assessed the redesigned side airbag module to ensure injury risks had been reduced prior to implementing the new system. To facilitate this, 12 redesigned side airbag deployments were conducted using the same procedures as Part I. Results indicate that the re-designed side airbag has effectively mitigated elbow injury risks induced by the original side airbag design. It is anticipated that this study will provide researchers with additional injury criteria for assessing upper extremity injury risk caused by both military and automotive side airbag deployments.

Journal Article↗
PubMed2003

Sacroiliac joint dysfunction in athletes.

The sacroiliac (SI) joint is a common source of low back pain in the general population. Because it is the link between the lower extremities and the spine, it sustains even higher loads during athletic activity, predisposing athletes to a greater probability of joint dysfunction and pain. The diagnosis and treatment of SI joint dysfunction remains controversial, due to complex anatomy and biomechanics, and a lack of universally accepted nomenclature and terminology, consistently reliable clinical tests and imaging studies, and consistently effective treatments. This article clarifies these issues by presenting a model of SI joint anatomy and function, a systematic approach to the diagnosis of dysfunction, and a comprehensive treatment plan.

Adult↗
PubMed2003

Pathophysiology of pain in sports.

The art and science of the management of musculoskeletal pain has advanced significantly over the past several years. With greater understanding of the nervous system's response to pain, and the biochemistry of this response, practitioners have a wider range of treatment options than ever before. The recognition of the importance of pain control in the recovery from musculoskeletal injury has resulted in the development of newer and more aggressive pain management strategies employing a variety of clinical techniques. Central to the appropriate use of these techniques is an understanding of physiology, psychology, and biochemistry of the pain response.

Analgesics↗