Correcting Muscle Imbalance in Helicopter Pilots with Pilates

Transcription

1 Correcting Muscle Imbalance in Helicopter Pilots with Pilates Tara Businski October 9, 2014 Oceanside/South Pasadena, CA 2013

2 Abstract Many professions require people to work in imbalanced or unnatural positions and piloting a helicopter is no exception. Cockpit ergonomics are poor and difficult to correct due to crash safety concerns. As a result, many helicopter pilots develop back pain and postural deviation such as a flexed c-shape to the normally s-shaped spine, rounded shoulders, and head extended anteriorly and neck hyperextended (nose up). A consistent Pilates program focused on correcting these postural deviations can prevent or correct the muscle imbalances that result. The conditioning program outlined in this study focuses on spinal mobilization, stretching the hip flexors, and strengthening upper back extensors to restore the spine and torso to a healthy posture and reduce or prevent back pain. 2

3 Table of Contents Abstract Anatomy Case Study Conditioning Program Conclusion References

4 Anatomy Up to 88% of helicopter pilots experience low back pain in during or immediately after flying and 29-34% of those experiencing pain say it affects their job performance (Phillips 2011, Sheppard 2011). Since pilot errors can have catastrophic effects, understanding the causes and effectively preventing pain in this population is important for safety of flight. The most common cause of low back pain in helicopter pilots is their flying posture. The cockpit is set up such that pilots sit in a posture commonly referred to as a helo hunch in which the normal s-shaped spine is held in a flexed c-shape with the head extended anteriorly and neck hyperextended (nose up) (Sargent and Bachmann 2006). After extended periods in the hunched posture, the anterior edges of the vertebrae are pushed together and posterior edges are pulled apart resulting in uneven pressure on intervertebral disc. Outside the cockpit, pilots will typically exhibit flattening of the normal lumbar lordosis which, left untreated, can cause pathological changes over time (Vallejo et al. 1998). At the muscular level, these posture deviations will cause overstretching and weakness in the erector spinae and multifidus muscles and shortening of the hip flexors and rectus abdominis (Fig. 1). The spinal muscles require strengthening to provide the required support and the hip flexors should be stretched. Upper back muscles should also be strengthened to minimize rounded shoulders that often accompany the c-shaped spinal position. Attention should also be paid to maintaining head alignment when working with this type of client due to the hyperextended and anterior head position typically seen in the cockpit. Finally, helicopter pilots lean slightly left due to flight control placement. The left lean prevents spinal musculature from relaxing and causes spasms and asymmetrical development in 4

5 a) b) Figure 1. a) Posterior view of the superficial (right) and deep (left) muscles of the spinal column. b) Anterior view of the muscles of the hip (Martini, Timmons, & Tallitsch 2012). those muscles (Vallejo et al. 1998). This asymmetry will also affect erector spinae and multifidus muscles in addition to abdominal obliques and these muscles should be both strengthened and stretched to alleviate spasms and work to balance the asymmetrical development. Case Study John, age 27, represents a typical military helicopter pilot at the point in his career when lower back pain usually begins to interfere with flight duties. He has 1000 total flight hours and flies two to four hours per flight with a monthly average of 50 hours. His lower back pain begins approximately 2 hours into a flight and is worse in flight regimes that require more attention to 5

6 flight instruments and less time spent looking outside, such as poor weather. The pain is most intense during flight, but he often experiences residual pain outside the cockpit, especially when sitting for extended periods. Going to a chiropractor has helped but he is looking for other options to improve symptoms between visits. John flies in the helo hunch posture typical for rotary wing pilots. Since this posture is predicated on cockpit ergonomics and design, there is little that can be done to remove the cause of the back pain. Supplemental seat cushions and lumbar support pads are not authorized due to safety concerns in case of emergency egress (Mohler 2000), so John will use Pilates to correct strength and flexibility imbalances in his postural muscles and develop the core strength required to maintain a healthy back during flights. Conditioning Program The following exercises will be emphasized throughout John s Pilates sessions to correct his muscle imbalances. Not all exercises will be done in each session, the sequence will be adjusted to facilitate flow, and other exercises may be included or substituted to add variety and prevent complacency. Warm-up Footwork Abdominal Work Block Exercises Desired Results Pelvic curl Warm up while opening the Spine twist supine hip flexors and isolating Chest lift rotation of upper and lower Chest lift with rotation torso. Parallel heels and toes V-position toes Open V heels and toes Calf raises Prances Single leg heels and toes Cat stretch kneeling Torso press sit Teaser (Reformer) Teaser 1 (Cadillac) Breathing with PT Bar Using the reformer allows John s hip flexors to extend further than on other equipment and accommodates his tight hamstrings. These abdominal exercises are coupled with back extension or spinal articulation to mobilize the spine and help correct John s 6

7 Hip Work Spinal Articulation Stretches Full Body Integration Arm Work Full Body Integration Leg Work Lateral Flexion/Roation Back Extension Bottom lift with RU Bar Single leg supine series Single leg side series Bottom lift Bottom lift w/ extension Standing lunge Pole series Down stretch Stomach massage series Kneeling cat stretch Saw Arms kneeling series Shrugs Shoulder adduction, single and double arm Long back stretch Balance control back Hamstring curl Hip opener Mermaid Side over (Reformer or Ladder Barrel) Side lift (Cadillac or Step Barrel) Breastroke Swan on floor Prone 1 and 2 rounded shoulders. Working the hips independently will help identify and correct lateral imbalances. Strengthen hamstrings to counter tight hip flexors and increase lumbar mobility. Stretch hip flexors and hamstrings while accommodating tight muscles. The pole series will help stretch John s chest muscles to address his rounded shoulders. These movements will help John mobilize his spine, stretch his hamstrings, and strengthen his upper back extensors. Trunk stabilization in the arms kneeling series will help address John s rounded back and the shoulder exercises will help open his rounded shoulders. Working up to these movements to stretch the shoulders and open the chest while extending the hip flexors. These leg exercises will help strengthen John s extensors to help counter his tight flexors. The isolation of torso rotation from the hips in mermaid will help strengthen and stretch the spinal stabilization muscles. Side overs and side lifts will correct lateral imbalances that cause John s left lean. These back extension exercises all incorporate the shoulders or upper back while discouraging the flattening of 7

8 8 John s lumbar spine.

9 Conclusion Consistent Pilates practice can help prevent and correct the muscle strength and flexibility imbalances commonly seen in helicopter pilots. Left untreated, these imbalances can result in major injuries and pathologies that could potentially require invasive medical intervention or result in lifelong pain. The program outlined above is a guide to the types of exercises that can lead to correction of the imbalances or, if used before pain begins, can be preventative for anyone embarking on a flying career. 9

10 References Martini F.H., Timmons, M.J., Tallitsch, R.B. (2012). Human Anatomy. Glenview, IL: Pearson Education. Mohler S.D. (2000). Lower back pain is a common complaint, but precautionary practices help pilots cope. Flight Safety Foundation: Human Factors and Aviation Medicine 47(3): 1-6. Phillips A.S. (2011). The scope of back pain in Navy helicopter pilots (Thesis) Naval Postgraduate School, Monterey. Sargent P. and Bachmann A. (2006). Back pain in the Naval rotary wing community. Retrieved June 14, 2013 from Sheppard C. (2011). Helicopter seating forum highlights back and neck pain. Retrieved June 14, 2013 from Highlights-Back-and-Neck-Pain_74231.html. Vallejo P., Lopez J. Rios-Tejada F., Azofra J., Del Valle J., Velasco C., Garcia-Mora L. (1998). Low back pain in helicopter pilots. Current Aeromedical Issues in Rotary Wing Operations Symposium; 1998 October 19-21; San Diego, USA. RTO MP