Abstract
Background A transection of the short head of the biceps brachii muscle is an uncommon injury seen among outpatient sports physical therapy clinics. The highest rate of occurrence and the majority of literature that discusses this specific injury are related to US military parachuting. The purpose of this case report is to outline the episode of care from 2 days after the injury through 6 months of conservative treatment, which consisted of therapeutic exercise, manual therapy, and cryotherapy, within an outpatient sports physical therapy clinic in a military setting.
Case Description This case report outlines the initial evaluation, diagnostic imaging, treatment, and 6-month follow-up measures for a 23-year-old male patient who sustained a static line injury resulting in a full-thickness tear of his biceps brachii muscle and a partial tear of the coracobrachialis muscle.
Outcomes The individual described in this case report reported having no functional limitations in regard to his job and leisure activities or any pain at his 6-month follow-up, with a score of 0% noted on his Shortened Disabilities of the Arm, Shoulder, and Hand Questionnaire (QuickDASH). Isokinetic testing revealed a 39.1% decrease in elbow flexion peak torque and a 60.8% decrease in elbow flexion total work output at this same follow-up interval.
Discussion In determining the appropriate course of treatment for this injury type, conservative physical therapy intervention should be considered as a viable treatment option, as there have been no decisive studies to suggest superior outcomes with other methods such as surgical correction. It is further recommended that research be conducted in an effort to prevent such injuries from occurring, as this mechanism of injury has proven to be much higher among the US military population compared with other military populations.
A closed transection of the biceps brachii muscle is rarely seen in outpatient sports medicine clinics. This injury was first documented in 1934 by Gilcreest,1 although the mechanism of injury was not reported. Over the last several decades, increasing literature on this topic has been published, with the highest rate of occurrence being associated with US military parachute training.2,3 Further literature demonstrates this injury with recreational sports, such as case reports that outline the injury secondary to arm wrestling and water sports.4–7
This case report describes a 23-year-old male soldier who sustained a full-thickness tear of the short head of the biceps brachii muscle, in addition to a partial tear of his coracobrachialis muscle, during a routine training maneuver. This individual was a member of an elite special operations airborne unit who sustained his injury due to becoming entangled in his static line upon jumping from an aircraft during an airborne proficiency jump.
The prognosis for biceps brachii muscle transections varies greatly depending on the extent of the tear and the treatment approach followed afterward. To date, the current literature has examined 2 separate treatment options: surgical versus nonsurgical. In the nonsurgical literature, no rehabilitative protocols have been published that outline recommendations or treatment approaches. This patient was treated nonoperatively in a sports physical therapy clinic, given the risk for surgical complications and lack of definitive evidence to suggest superior results from obtaining surgical correction. Additional factors in considering surgical versus conservative treatment included time of recovery and return to full duty.
The purposes of this case report are to document the episode of care for this individual in order to provide further understanding and to outline expectations for treating such injuries in a conservative manner. Furthermore, this case report utilized pilot data collected prior to the injury that provided a quantitative evaluation of the patient's functional strength with various performance tests. No other literature was found that provided a comparative analysis to determine overall functional changes related to therapeutic intervention.
Patient History/Review of Systems
A 23-year-old, active duty, male service member with 10 months of active service was seen at a sports physical therapy clinic 2 days after sustaining a static line injury while conducting airborne training. His height was 181.6 cm (71.5 in), and he weighed 72.6 kg (160 lb), as noted on his initial intake form. The soldier was seen immediately following his injury in a military treatment facility emergency department. Plain radiographic films were completed, at which time bony pathology was ruled out. The patient was discharged with a standard sling for immobilization and nonsteroidal anti-inflammatory drugs for pain and edema control.
On the initial evaluation, the patient's chief complaint was pain over the superior medial border of his left biceps brachii muscle (his nondominant upper extremity), with associated weakness during supination and elbow flexion. He further demonstrated mild edema over the proximal one third of his upper arm in addition to a superficial abrasion running diagonally from medial to lateral in a superior direction consistent with his mechanism of injury. A small, palpable deficit was identified directly beneath this abrasion, consistent with a partial biceps muscle tear, as documented by several authors.2,3,8,9 The patient had no other comorbidities and reported having no history of orthopedic pathology or disease.
Mechanism of Injury
A static line injury sustained during airborne training occurs when the individual paratrooper inadvertently routes a static line between the thorax and upper extremity, which pulls the arm violently into abduction and external rotation upon exiting an aircraft. A static line is a 1.9-cm-wide (0.75-in-wide) piece of nylon webbing that connects a jumper's parachute deployment system to a steel cable that runs the length of the aircraft. The purpose of the system is to quickly deploy an individual's parachute after he or she exits the aircraft. A jumpmaster is a specialty qualified service member who directs and facilitates movement within the aircraft and ensures that proper safety procedures are followed.
The most common reasons why static line injuries occur are: (1) if the paratrooper in front of the entangled soldier does not properly hand off his or her static line, the jumpmaster will not be able to adequately control the excess static line, and (2) if the following jumper does not make eye contact with the jumpmaster to ensure that the jumpers are cleared to proceed out of the door, the suspended webbing will be caught between the jumper's arm and thorax as the static line is handed off while simultaneously turning to exit the door. As the paratrooper exits the aircraft, he or she is trained to bring his or her arm to full adduction, with the elbow bent at 90 degrees and hands covering the sides of the reserve parachute in a tightly held posture.
After exiting the aircraft in this rigid body position with the static line under the arm, upon reaching the end of the free running line, the paratrooper's arm will be forced into maximal abduction and external rotation, with significant tension being created at the mid-substance of the biceps brachii muscle. This type of high-energy force is typically strong enough to create a closed transection of the muscle belly.
Examination
During the initial evaluation, shoulder and elbow ranges of motion (ROMs) were measured, using a goniometer, in all of their respective degrees of freedom, and standard manual muscle testing was done for both upper extremities. The patient's grip strength of the involved hand also was assessed using a handheld dynamometer and compared with that of the uninvolved hand, with an average of 3 attempts being recorded.
The integumentary system was assessed both visually and with palpation. Moderate edema was noted over the superior medial border of his left biceps brachii muscle, with a superficial abrasion seen over the corresponding area. With palpation over this area, a small defect was noted, with a minor step-off felt within the muscle belly. Only minor ecchymosis was seen at the time of the initial evaluation 2 days after the injury.
The patient demonstrated normal capillary refill and a symmetrical radial/ulnar pulse. His neurological system was screened using light touch and 2-point discrimination, and he demonstrated no sensory loss compared with the contralateral side.
The patient was questioned regarding any previous orthopedic injuries, medications, and drug allergies, and he responded negatively to all of these queries. At the conclusion of the initial evaluation, the patient was provided with the Shortened Disabilities of the Arm, Shoulder, and Hand Questionnaire (QuickDASH), a clinical outcome measure that has been shown to have good reliability and validity in measuring disabilities of the upper extremity.10
Further objective data that were compiled for this patient, which are unique to this case report and not found in other literature, were obtained using a full functional screen that was completed for this patient 3 weeks prior to his injuries and repeated 6 months after the injury to provide a broad comparison of his overall functional status. This functional screen covered a spectrum of performance metrics that included upper and lower body strength, speed, and power and are typically measured twice per year as a standard measure of overall fitness. For the purposes of this case report, only the upper body measurements are provided, including data obtained for metronome push-ups and standard pull-ups. Provided below are the specific standards for each task.
Metronome push-ups: standard push-ups that are completed using a metronome set at 60 beats per minute. The individual is instructed to move into the up position, with elbows fully extended and the body forming a generally straight line on one beat, and to move to the down position on the following beat while not allowing one's chest to rest on the ground. This cycle is continued until the individual is unable to keep pace with the metronome. After 2 consecutive missed beats, the test is terminated.
Pull-ups: standard pull-ups, with the starting position being identified as hanging from the bar with elbows fully extended and the body remaining at rest. Each repetition consists of pulling oneself up until the chin is cleared over the bar and returning to the start position. The test is terminated when the individual is unable to continue in this fashion.
Due to the patient's high-energy mechanism of injury, overall presentation with weakness in elbow flexion, and supination combined with the presence of a palpable defect over the short head of the biceps muscle, a standard magnetic resonance image was ordered to determine the full extent of soft tissue damage. Within 48 hours, the magnetic resonance imaging results were obtained, which demonstrated a full-thickness tear of the short head of the biceps brachii muscle as well as a small interstitial tear of the coracobrachialis muscle (Figs. 1A and 1B, respectively). This injury was consistant with musculoskeletal pattern 4D (“Impaired muscle performance associated with connective tissue dysfunction”), as defined by the Guide to Physical Therapist Practice.11 After imaging was completed, an orthopedic surgeon was consulted, and conservative care was decided to be the treatment of choice.
Magnetic resonance images: (A) Image demonstrating the short head of biceps brachii muscle that is distally retracted and residing in the middle third of the arm. The arrow indicates the separation of the muscle belly from the proximal tendon. (B) Image showing a hyperintense T2 signal over the mid-belly of the coracobrachialis muscle consistent with a partial tear.
Intervention
Phase 1 (Weeks 1–3)
The initial treatment consisted of relative immobilization, with the arm placed in a standard upper extremity sling with the shoulder internally rotated to the abdomen and elbow bent at 90 degrees. The patient was instructed to wear the sling for 3 weeks and was allowed to doff the sling only while performing his therapeutic exercises. The initial treatment plan of care consisted of gravity-assisted elbow ROM for extension and active-assisted ROM for elbow flexion, supination, and pronation. Active-assisted ROM for the shoulder and grip strengthening exercises also were performed, and the sessions were completed with a cold compression wrap at approximately 1°C with gravity-assisted elbow extension. All of the therapeutic exercises were aimed at restoring the patient's elbow ROM, decreasing edema, managing pain, and preventing decreased strength and ROM in the hand and wrist. The outlined interventions were conducted 4 or 5 times per week in the physical therapy clinic and independently on the other days.
Phase 2 (Weeks 4–6)
This phase began with a gradual discharge from the shoulder sling and progressive active ROM to end-range. Light resistive exercise also was initiated for both elbow and shoulder flexion and supination using TheraBand (The Hygenic Corp, Akron, Ohio). Strengthening of the parascapular muscles was further added in an effort to prevent scapular dyskinesia or instability. The ROM exercises were gradually decreased over this phase as the patient's ROM returned to normal, and added strengthening exercises were provided. Cryotherapy was used as needed when pain or discomfort was noted. Prior to beginning ROM and strengthening exercises, he completed a dynamic movement preparation consisting of use of the upper body ergonometer for 8 to 12 minutes. The therapeutic exercises consisted of standard bicep curls, reverse curls, hammer curls, wall push-ups, and scapular rows; shoulder proprioceptive neuromuscular facilitation D1–D2 flexion patterns, and resisted supination.
Phase 3 (Weeks 7–9)
Regimented strength progression training was the staple of this phase. Continued effort was aimed at scapular stability to prevent compensatory movement patterns from forming. The patient also was transitioned to more functional tasks for his given profession such as standard push-ups and pull-ups. He progressed from doing incline push-ups with his hands on a 30.5-cm (12-in) box to doing decline push-ups with his feet on the box. Pull-ups were initiated using gymnastics rings positioned about shoulder height and allowing partial weight bearing through his heels; he performed these pull-ups with sub–body-weight resistance. At the completion of phase 3, he was released to progress to weight training to tolerance and instructed not to progress greater than 5% total weight per week.
During the course of treatment for phases 2 and 3, the patient was seen 2 or 3 times per week, depending on his work schedule. Each exercise was completed for 2 or 3 sets of 8 to 10 repetitions.12 When he was able to complete 3 sets of 10 repetitions of any given exercise, the resistance was increased. After phase 3 was completed, the patient was released to perform his duties at work to tolerance, with restrictions against performing airborne training until 5 months postinjury in an effort to avoid any submaximal or maximal eccentric loading of the biceps brachii muscle to prevent reinjury.
Outcome
The patient was noted to have demonstrated symmetrical ROM in all planes after the initial 4 weeks of treatment. At approximately the same time, he no longer demonstrated any edema or ecchymosis, and his superficial abrasion was fully healed. He also showed no deficits regarding manual muscle testing with the exception of forearm supination, which demonstrated only moderate strength, as noted during the 6-month follow-up evaluation. The patient reported having no pain with palpation or any functional deficits with activities of daily living or with his occupational duties. During the patient's episode of care, his neurological and circulatory systems remained symptom-free and without any deficits noted.
At the conclusion of the patient's formal rehabilitation, he completed the QuickDASH and scored 0%, which is consistent with his report of no functional deficits. He self-reported his pain level as 0/10 on the visual analog scale. Table 1 outlines all of the objective measurements as noted during the initial evaluation and at the 6-month follow-up.
Physical Examination Objective and Clinical Outcome Measuresa
The functional performance test completed 3 weeks prior to injury and again 6 months after the date of injury demonstrated that the patient did have a decline in functional performance for both metronome push-ups and standard pull-ups. He trended in an overall negative manner, with a decrease in total repetitions of 18% and 27%, respectively.
After this service member had completed his formal rehabilitation program, isokinetic testing was completed in an effort to further evaluate any strength deficits using the Biodex System 3 (Biodex Systems Inc, Shirley, New York). Isokinetic testing was not completed prior to the intervention, as it was contraindicated due to the transected biceps muscle and might have resulted in greater injury and increased pain. The key data points that were collected included peak torque and maximal repetitions of total work. Peak torque is a measure of the highest muscular force output during a given repetition, which indicates the muscle's strength capabilities. A maximal repetition of total work is defined as the total muscular force output for the repetition with the greatest amount of work. Work is indicative of a muscle's capability to produce force throughout the ROM.13 The patient's isokinetic measurements at 6 months postinjury are presented in Table 2. These measurements were taken at 120°, 180°, and 300°/s to gather as much functional information about the patient as possible. These differences infer how the patient may function with different tasks that require more ballistic-type movements such as throwing a grenade. Data for supination and pronation were not collected due to lack of proper equipment at the facilities where the testing was completed.
Isokinetic Measurements at 6 Months Postinjurya
The patient demonstrated an overall positive trend for shoulder peak torque while going into flexion by greater than 20% at both ends of the velocity spectrum. The largest deficits noted for peak torque were for elbow flexion and extension, showing a decrease of 39.1% and 36.3%, respectively, measured at 120°/s. He further demonstrated significant decreases in total work output (60.8% for elbow flexion and 48.3% for elbow extension) at the same velocity.
Discussion
The intent of this case report is to demonstrate the functional outcomes that may be anticipated when pursuing conservative treatment for this type of injury. Heckman and Levine2 reported the strength differences between patients who had undergone surgery and those who had not to be 76.5% and 53%, respectively, compared with a control group and allocating for hand dominance. Askew et al,14 in their study of isometric elbow strength in individuals who were healthy, noted that the dominant upper extremity was anticipated to produce 6% more force compared with the contralateral side.
Previous studies have provided a myriad of recommendations regarding length and degree of immobilization.2,3 When deciding on operative versus nonoperative treatment, there have been no decisive data that have been comprehensive in nature to suggest one course of action that is superior in the results attained. Furthermore, Carroll and Hamilton15 reported that 100 patients with biceps brachii muscle ruptures who pursued conservative treatment were able to return to work sooner and had little to no residual disability compared with patients who underwent operative interventions.
The patient in this case report was able to return to work relatively quickly and had limited functional deficits after completing a full course of conservative physical therapy intervention. With the functional measurements provided that were ascertained prior to his injury and again measured 6 months postinjury, one may have a better outlook on the potential functional changes that can be anticipated, although a more robust data set of premorbid functional measurements would be beneficial.
When considering long-term outcomes, one may argue that this individual is at an increased risk for reinjury secondary to the asymmetries noted during isokinetic and functional testing. Further research is recommended to determine whether these injury rates are different than the unaffected side, both for those individuals who remained in special operations and for those whose occupations changed, resulting in less strenuous activity requirements. Lastly, when considering the risk of operative interventions such as infection and the inherent risk of anesthesia, it is logical to consider this conservative course of action as a viable treatment regimen.
The obvious solution to this varied problem set would be prevention. As Huller and Taggan16 noted in their retrospective study of 83,718 jumps among members of the Israeli Defense Forces, no static line injuries were reported. Although multiple preventative strategies have been implemented since the inception of airborne operations in the US military, little to no reduction in emergency consultations has been noted.17 Further research, therefore, is recommended in the prevention of such injuries and modification of current practices.
Footnotes
The author thanks Dr Joseph Vorro for editorial and proofreading assistance.
The views expressed in this article do not reflect the official views of the US Department of Defense, the US Army, or the US government.
- Received July 23, 2013.
- Accepted November 8, 2013.
- © 2014 American Physical Therapy Association
References
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