Overview
Injury to the brachial plexus trunk is a significant concern, particularly in athletic populations where forceful movements and compromised trunk stability can predispose individuals to these injuries. The brachial plexus, a network of nerves originating from the spinal cord, provides motor and sensory innervation to the upper extremity. Trunk injuries within this network can lead to substantial functional impairment, affecting motor function, sensation, and overall quality of life. This guideline synthesizes current evidence to provide clinicians with a comprehensive understanding of the epidemiology, clinical presentation, diagnosis, and management strategies for brachial plexus trunk injuries, with a focus on athletic populations.
Epidemiology
Brachial plexus trunk injuries, especially in collegiate athletes, predominantly occur through non-contact mechanisms, accounting for approximately one-third of all athletic injuries [PMID:26537806]. These injuries often involve the upper extremity, highlighting the vulnerability of this region during dynamic activities. Gender differences also play a role, with female athletes exhibiting greater hip and trunk movement compared to males, potentially increasing their risk of non-contact injuries [PMID:35588101]. This heightened movement may reflect compromised trunk stability, which can be a critical risk factor for brachial plexus injuries during forceful athletic maneuvers. Understanding these demographic trends is crucial for targeted prevention strategies and early intervention in high-risk groups.
Clinical Presentation
The clinical presentation of brachial plexus trunk injuries can vary widely but often includes symptoms such as pain, weakness, and sensory deficits in the affected arm. Female athletes, due to their greater hip and trunk movement, may present with more pronounced trunk instability, which can exacerbate injury mechanisms involving the brachial plexus [PMID:35588101]. Clinicians should consider assessing trunk stability through measures of range of motion (ROM) and strength, as these assessments demonstrate good-to-excellent reliability [PMID:34092197]. However, coordination measures show lower reliability, suggesting that while ROM and strength evaluations are more consistent, they should be complemented with functional assessments to fully capture the complexity of trunk involvement. Additionally, the differential recruitment patterns of thoracic and lumbar extensors at varying exercise intensities [PMID:26003038] underscore the importance of evaluating muscle balance and coordination in athletes. This holistic approach helps identify underlying imbalances that may contribute to brachial plexus injuries.
Diagnosis
Diagnosing brachial plexus trunk injuries requires a multifaceted approach, incorporating both clinical examination and objective measurement tools. Hand-held dynamometers, commonly used for assessing muscle strength, have been shown to underestimate strength compared to more precise load cells [PMID:34092197]. This discrepancy highlights the necessity for clinicians to consider these measurement differences when evaluating strength deficits in patients. Electromyographic (EMG) evaluations provide additional insights, particularly in understanding muscle activation patterns during different exercise intensities. Direct estimation of one-repetition maximum (1-RM) closely correlates with load and trunk extensor activity during high-intensity exercises, whereas indirect estimation methods are more accurate for lower-load training scenarios [PMID:26003038]. Integrating these advanced assessment techniques can enhance diagnostic accuracy and guide tailored rehabilitation plans.
Management
The management of brachial plexus trunk injuries focuses on restoring function, reducing pain, and preventing further injury. Core stability training, widely accepted for injury prevention and rehabilitation, warrants careful consideration given the current evidence base [PMID:26537806]. While beneficial, the sufficiency of existing evidence supporting its effectiveness remains questionable, necessitating a cautious approach and individualized rehabilitation plans. Kinoshita et al. emphasize the importance of vertical trunk function, as assessed by the Trunk Righting Test (TRT), in athletic performance and injury prevention [PMID:35588101]. Improved vertical trunk stability correlates with enhanced knee extension strength, dynamic balance, and overall functional performance, which are critical for activities like jumping and cutting. Therefore, incorporating TRT into rehabilitation protocols can be pivotal in restoring functional stability.
Refinement of assessment methods, particularly for strength and ROM evaluations, has shown promise in improving reliability and, consequently, rehabilitation outcomes [PMID:34092197]. Clinicians should consider optimizing these protocols to better monitor progress and adjust interventions accordingly. Tailoring exercise regimens based on EMG findings, such as using direct 1-RM estimation for high-intensity training and indirect methods for lower loads, can optimize muscle activation and recovery [PMID:26003038]. This personalized approach ensures that rehabilitation efforts are both effective and efficient, addressing the specific needs of each patient.
Key Recommendations
In clinical practice, these recommendations aim to provide a structured yet flexible framework for managing brachial plexus trunk injuries, emphasizing the importance of comprehensive assessment and individualized rehabilitation approaches.
References
1 Kazuaki K, Ishida K, Hashimoto M, Nakao H, Nishizawa Y, Shibanuma N et al.. The effects of vertical trunk supportability improvement on one-leg rebound jump efficiency. PloS one 2022. link 2 Silfies SP, Ebaugh D, Pontillo M, Butowicz CM. Critical review of the impact of core stability on upper extremity athletic injury and performance. Brazilian journal of physical therapy 2015. link 3 Smith R, Connick M, Beckman E, Hogarth L, Nicholson V. Establishing the reliability of instrumented trunk impairment assessment methods to enable evidence-based classification in Para swimming. Journal of sports sciences 2021. link 4 De Ridder E, Danneels L, Vleeming A, Vanderstraeten G, Van Ranst M, Van Oosterwijck J. Trunk extension exercises: How is trunk extensor muscle recruitment related to the exercise dosage?. Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology 2015. link
4 papers cited of 5 indexed.