No, neck strengthening exercises may not prevent cerebral concussions (knockouts) in boxing per study 'Peak accelerations of the head experienced in boxing'. The response of the head-neck system to an external force had been established by forcing the torso of a subject to move in a fore and aft direction, in a sinusoidal manner at various frequencies. In a realistic boxing situation a ‘safe level’ can be exceeded by a factor of 4 when the estimated pulse is used in conjunction with Gadd Severity Index developed for road safety.
The results of the study were,
The duration of a typical pulse of force, as encountered in boxing, was measured, and hence it was inferred that in this situation the head is mass-controlled; i.e. the effect of the rigidity and damping of the neck is negligible.
Regarding boxing knockouts,
Along with legitimate lesions sustained by competitors, for example as a result of cerebral concussion (knockout), there is a considerable risk of acute injuries to the head, heart, and bones in competitive boxing. Neuropsychological deficits last longer than most subjectively experienced consequences of blunt traumatic brain injury beyond the acute phase. Tests conducted on cerebrospinal fluid (CSF) verify previous nerve damage.
Repetitive brain trauma over a lengthy career may result in boxer’s dementia having neurobiological similarities to Alzheimer’s disease.
The recurrent head trauma in boxing may be associated with increased risk of chronic traumatic brain injury.
"Chronic traumatic brain injury (CTBI) associated with boxing occurs in approximately 20% of professional boxers. Risk factors associated with CTBI include increased exposure (i.e., duration of career, age of retirement, total number of bouts), poor performance, increased sparring, and apolipoprotein (APOE) genotype."
A majority of boxing-related fatalities result from traumatic brain injury. Biomechanical forces in boxing result in rotational acceleration with resultant subdural hematoma and diffuse axonal injury. There was a significant decline in mortality after 1983 which was hypothesized as the result of a reduction in exposure to repetitive head trauma (shorter careers and fewer fights), along with increased medical oversight and stricter safety regulations. Mandatory central nervous system imaging after a knockout could lead to a significant reduction in associated mortality.
- Rotational accelerations appeared to be the dominate response and were consistent with levels found in concussion of professional football players in the study 'Biomechanics of the head for Olympic boxer punches to the face' about head injury risks which combines data on the head impact response of a biofidelic dummy and the measured punch force of Olympic class boxers throwing straight punches.
Rotational acceleration had good linear correlation with weight class. Weight class also showed good correlation with punch force, jaw force, HIC, and head velocity. These results support previous epidemiological studies showing that head injuries occur more frequently in the heavier weight classes36 and the general mechanics of the boxing punch.37 While weight was a good predictor, punch force had a stronger correlation with HIC, rotational acceleration, and head velocity. In addition, punch force also correlated with translational acceleration. Hand velocity did not seem to affect the severity of impact. This means the effective mass of the boxer’s punch is more important in increasing the severity of a blow.
However, conclusion of another study was that neither the translational nor the rotational acceleration reached a level that was injurious to the boxer based on the tolerance limit of 200 g for translational acceleration and 4500 rad/s2 for rotational acceleration and repeated sub-concussive blows were the injury mechanism for mild traumatic brain injury MTBI.
Research is necessary to determine the outcomes of injury, particularly the long-term neurologic outcome differences between sexes since male boxers have a higher rate of knockout and technical knockouts than female boxers.
No compelling evidence is available to suggest that regular magnetic resonance imaging of the brain, rigorous medical supervision, or currently practised safety measures will influence or prevent the development of chronic traumatic brain injury. However, because today's boxers have shorter careers and reduced exposure to repetitive head trauma, the likelihood of this condition developing is probably low.
Effects of concussion a.k.a. Mild traumatic brain injury
Immediate physiological changes such as multilayered neurometabolic cascade in which recovery of affected cells typically occur, although under certain circumstances a small number might degenerate and die. The primary pathophysiologies include ionic shifts, abnormal energy metabolism, diminished cerebral blood flow, and impaired neurotransmission.
Elevations of glutamate and potassium, early hyperglycolysis and glucose metabolic syndrome. Metabolic recovery generally takes weeks to months after moderate to severe TBI.
Neck strength studies
When exploring the biomechanics of head and neck movement, evidence indicates that brain injury is associated with head acceleration. Minimizing head acceleration has been a focus of recent research in many sports, including American football and soccer.
Concussions occur as a result of a direct or indirect force that is applied to the head that results in the sudden acceleration/deceleration of the brain . In general, it is not the velocity of the athlete or the force of impact that is being measured, but rather the change in velocity or acceleration of the cranium that is measured by helmet-based sensors.
Empirical formulations such as the Gadd Severity Index (GSI) and the Head Injury Criterion (HIC) predict when a single uniform, linear acceleration of the head may lead to brain injury. However, the cumulative effects of repeated accelerations remain unknown.
Force can also cause an acceleration which is rotational or translational of the skull/brain structure and acceleration creates intracranial pressures and movement and distortion of brain tissue through strain. Optimal neck strengthening interventions for concussion risk mitigation are not known.
Identifying differences in overall neck strength may be useful in developing a screening tool to determine which high school athletes are at higher risk of concussion per Collins CL et. al. 2014.
Overall neck strength (p < 0.001), gender (p < 0.001), and sport (p = 0.007) were significant predictors of concussions in unadjusted models. After adjusting for gender and sport, overall neck strength remained a significant predictor of concussion (p = 0.004). For every one pound increase in neck strength, odds of concussion decreased by 5 % (OR = 0.95, 95 % CI 0.92-0.98).
However another study by Jason Mihalik et.al in 2011 conflicts with the above finding that
Our hypothesis that players with greater static neck strength would experience lower resultant head accelerations was not supported. This contradicts the notion that cervical muscle strength mitigates head impact acceleration. Because we evaluated cervical strength isometrically, future studies should consider dynamic (ie, isokinetic) methods in the context of head impact biomechanics.