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  • 1. CASE REPORTNAJSPT Rehabilitation of a Female Dancer with PatellOfemoral Pain Syndrome: Applying Concepts of Regional Interdependence in Practice Caitlyn Welsh, PT, MPTa William J. Hanney, PT, DPT, ATC/La,b Laura Podschun, PT, MPT, OCSa Morey J. Kolber, PT, PhD, OCS, Cert MDTCcABSTRACTDue to complex movements and high physical demands, CORRESPONDENCEdance is often associated with a multitude of impairments William J. Hanney, PT, DPT, ATC/Lincluding pain of the low back, pelvis, leg, knee, and foot. University of Central FloridaThis case report provides an exercise progression, empha- Program in Physical Therapysizing enhancement of strength and neuromuscular per- HPA 1 D Suite 258formance using the concept of regional interdependence Orlando, FL 32816in a 17 year old female dancer with patellofemoral pain Phone: 407-823-0217syndrome. Email: whanney@mail.ucf.edua Florida Hospital Sports Medicine and Rehabilitationb University of Central Florida Orlando, FL USAc Nova Southeastern University North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 85
  • 2. INTRODUCTION these motions may depend on the strength of proximalDance often involves a complex sequence of movements muscle groups that are antagonistic to these movements.10and high physical demands of strength, stability, and flex- Proper hip strength and neuromuscular control, particu-ibility. Due to intricate choreography and challenging larly of the gluteus medius and hip external rotators,performance schedules dancers are potentially at risk for enhances knee stability by controlling the pelvis and lim-injury. These physical requirements of dance, which iting hip adduction and internal rotation that result ininclude prolonged bouts of training and explicit physical increased knee valgus during activity.11 In the absence ofcontrol of their body, make physiologic training just as sufficient proximal strength or muscular control, theimportant as skill development for injury prevention. femur may adduct and internally rotate, exaggerating lat- eral patellar contact due to the valgus moment.12-14The physical demands of dance often result in injury, Repetitive activities with this mal-alignment may eventu-which in turn limit a dancers ability to perform. In a sur- ally lead to patellofemoral pain.10vey of 324 professional dancers, almost 50% reportedmissing between one and twenty-one days of exercise due Patellofemoral pain syndrome (PFPS), also known asto injury each year.1 Koutedakis and Jamuris1 reported anterior knee pain, remains a common orthopedic com-that 90% of injuries in dancers involve the low back, plaint2,6 occurring in approximately 1 in every 4 people.15pelvis, legs, knees, or feet. Prolonged bouts of training Those involved in athletics report an incidence ofwith inadequate rest, unsuitable floors, difficult choreogra- patellofemoral pain greater than 25%.10,15 The condition isphy, and insufficient warm-ups are among the factors that more common in women than men and most oftencontribute to dance injuries.2 In their paper, Koutedakis affects younger individuals between the ages of 10 and 35and Jamuris1 reviewed studies on male and female years.16 Unfortunately, this pain often becomes a chronicdancers, which suggested that supplementary exercise condition that may fail to respond to conservative meas-training, beyond that of dance training, can lead to ures.17improvements in muscle balance and strength. Symptoms of PFPS typically include the following: painStrength training decreases incidence of dance injuries, while ascending and descending stairs, squatting, or pro-without interfering with the key artistic and aesthetic longed sitting. Swelling, popping or grinding sensationsrequirements of a dancer.1 However, strength training has may be present, as well as incidences of knee buckling orgenerally not been considered a necessary component of giving way.18,19 The spectrum of symptoms varies greatlypreparation for success in dance.1 This idea is supported among individuals, with complaints ranging from achyby the view among dancers and choreographers that pain after activity to severe pain when rising from a chairstrength training may create a physique that is not com- or climbing stairs.16plimentary to the typical dancers aesthetic appearance.1 Many patients with anterior knee pain are eventuallyMacDougal et al3 found increases in muscle strength were referred to rehabilitation. Although PFPS is one of thenot necessarily accompanied by proportional changes in most common clinical conditions treated by orthopedicmuscle size. This finding suggests that strength training is and sports physical therapists, a consensus does not existclosely related to neural adaptations which increase mus- regarding how these patients should be managed.16cle strength.3,4 These neural mechanisms responsible for Differential diagnostic skills must be utilized to rule out astrength development include alterations in agonist-antag- range of inflammatory conditions, mechanical problems,onist co-activation, increases in motor unit firing rates and other conditions such as ligamentous injury,(rate coding), and changes in descending drive to the tendinopathy, bursitis, and muscle strain.18-20 Identifyingmotorneurons.3,4 the origin of the inflammation is important for developingPrevious authors have suggested that proximal factors a treatment plan that will result in prompt resolution ofsuch as hip and core weakness may contribute to anterior symptoms.16 Failure to do so may result in suboptimalknee pain.5-7 Additionally, authors have demonstrated that care and poor outcomes.16 Some of the various techniqueswomen exhibit movements associated with knee valgus commonly used to treat PFPS include non-steroidal anti-and hip internal rotation when compared to men during inflammatory medication, ice, quadriceps strengthening,specific movements.6,8,9 The ability of women to control North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 86
  • 3. hamstring and gastrocnemius stretching, patella taping or female. She presented with a slender build, as well as abracing, and orthotics.15,20 low waist-hip ratio of 0.7524,25 that is typically seen in dancers. She had no swelling or erythema of her left kneeVaughn21 highlighted the importance of a regional with visual inspection. The history of her current injuryexamination for a patient with non-specific knee pain, was insidious onset of approximately one-year duration,illustrating the concept of regional interdependence. With as previously noted.respect to musculoskeletal problems, regional interde-pendence refers to the concept that seemingly unrelated Functional Statusimpairments in a remote anatomical region may con- The patient had stopped dancing 3 weeks prior totribute to, or be associated with, the patients primary examination, per the orthopedic surgeons recommenda-complaint.22 In some cases, knee pain may be the sole tion. She reported difficulty walking or running forpresenting symptom when a more proximal or distal periods longer than 10 minutes due to pain. She alsostructure such as the pelvis, hip, ankle, or foot is at fault.23 reported that ascending and descending stairs at schoolIn such cases, the pain may be referred from a more prox- caused an increase in pain, which forced her to take theimal structure or be consequential to a remotely located elevator some days. The patient demonstrated unilateralimpairment that produces excessive stress on structures of squat with genu valgus collapse bilaterally with report ofthe knee, resulting in pain.21 mild retro patellar discomfort.The purpose of this case report is to demonstrate the Systems Reviewimportance of strength and neuromuscular training in a At evaluation the patient was 56" and 125 lbs with a bodyfemale dancer who presented with PFPS and highlight the mass index of 20.2 which is considered to be at the lowerimportance of a regional interdependence model of exam- end of a normal range.26 She reported a history of faintingination to identify the origin of knee pain. due to low blood sugar with no occurrences in the past two years. Also no previous injuries or surgeries were report-CASE DESCRIPTION AND HISTORY ed. An integumentary and neuromuscular screenThe patient was a 17-year-old female high school student revealed no gross deficits. Family medical history waswho participated in dance activities up to 18 hours a week. unremarkable.Pain was initially reported in the anterior/medial aspectof the left knee in December 2007 with no specific mech- Tests and Measuresanism of injury noted. The patient continued, despite Posturepain in the left knee, to dance on a regular basis. She Standing postural assessment demonstrated the patientsattempted to join the school cross-country team in the fall spine, hips, and knees were within normal limits (WNL)of 2008 but was unable to participate due to her knee with exception of increased external rotation bilaterally insymptoms. the lower quarter. Supine postural assessment revealing an increase in femoral anteversion, which lead to com-An orthopedic surgeon evaluated the patient in December pensations in weight-bearing. The patient also presentedof 2008 with no significant findings related to fracture, dis- with a Q-angle of 8 degrees bilaterally and the patella waslocation, or meniscal involvement which is consistent hypo-mobile on the left with medial to lateral glides. Inwith the presentation of PFPS. Further diagnostic testing prone the patient presented with rear foot varus of 5with X-ray and MRI revealed a bone bruise on the medial degrees bilaterally and a neutral forefoot when examinedfemoral condyle and thinning cartilage. The patient opted in subtalar neutral. Gait was assessed with the patientfor rest from dance and physical therapy. ambulating in bare feet at a self-selected pace for 30 feet and rapidly for 30 feet. No significant findings were foundINITIAL EXAMINATION during gait analysis and the patient had no complaints ofInitial Presentation pain.The patient was seen on December 31, 2008 for physicaltherapy examination with a chief complaint of left knee Range Of Motionpain along the inferior and medial pole of the patella. The The patients active range of motion (AROM) for all hip,patient appeared to be a healthy and athletic 17 year old knee and ankle, measurements were WNL and symmetri- North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 87
  • 4. cal bilaterally except for hip internal rotation with right Functional Outcome Measurementsinternal rotation (IR) measured at 29 degrees and left IR At initial examination the patient scored a 49/80 on themeasured at 39 degrees. Lower Extremity Functional Scale (LEFS).27,28 She also scored a 3.7/10 on the Patient-Specific Functional ScalePain (PSFS)29 in which the patient identifies specific functionalA 10 mm visual analog scale (VAS) was used to elicit an tasks which are limited and rates them zero to ten withobjective description of the patients pain level.26 The lower numbers reflecting greater levels of limitation.patient reported 8/10 pain during dance class, which wasthe activity that most aggravated the symptoms. Pain was ASSESSMENTalleviated to 0/10 with sitting or resting. The patient The patients primary impairment was knee painreported 5/10 pain levels with walking more than 10 min- secondary to non-traumatic sports related injury. Theutes on even or uneven ground, as well as ascending or physical therapy evaluation revealed an overall decreasedescending 10 steps at school. Symptoms were localized in strength and muscle imbalances. This is particularlyto the medial aspect of the knee around the medial joint the case for her hip musculature which is needed to per-line. No tenderness to palpation occurred during examina- form as a dancer. Weakness of the left hip abductor andtion. external rotator muscles allowed for increased anterome-Muscle Strength dial vector forces and disproportionate stress on theThe patients strength was measured using manual anterior/medial left knee. Due to pain while dancing, hermuscle testing as described by Daniels and orthopedic physician placed the patient on activity limita-Worthingham.26 (Table 1) Abdominal (rectus abdominus tions and no return to dance until after the first 4 weeks ofand obliques) were measured at 4/5 in supine position treatment. The prescription was to evaluate and treat onewith trunk flexion. The patient was unable to hold a time a week for 6 weeks due to unusually high co-pay andprone plank greater than five seconds before increasing financial limitations.After the initial examination, theher lordotic curve suggesting weakness. All measure- patient was treated once per week for three weeks, andments were taken in a pain free manner. then once every other week, for six total sessions.Table 1. Reported hip and knee strength measures. Plan of Care Design The rehabilitation program integrated aspects of a regional interdependence approach with a focus on improving muscular strength and coordination, correcting muscle imbalances, and enhancing neuromuscular con- trol. Physical therapy interventions were initiated with a home exercise program (HEP) following initial examina- tion. The patients initial home program included single leg exercises for hamstring, gluteus medius and gluteus maximus muscle strengthening, single leg squats, side planks with knees flexed, as well as instruction for trans- verse abdominus muscle contraction with all exercises.Special Tests & and Muscle Length Assessments The patient was instructed to perform exercises daily,Based on the patient complaints of left knee pain several completing two sets of ten for each exercise.special tests were performed to rule out ligamentous andmeniscal involvement. The patient tested negative bilat-erally for the following tests: Lachmans and anteriordrawer test for anterior cruciate ligament (ACL) stability,McMurrays test for medial and lateral meniscus, 90/90test for hamstring muscle length, Thomas test for iliop-soas and rectus femoris muscle length, and Obers test foriliotibial band length. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 88
  • 5. INTERVENTION Follow-up Visit 1AssessmentThe patient reported pain intensity of 6/10 VAS the week living and progression to return to dance that could befollowing the initial examination, with the symptoms carried over for home program due to limited visits. Themost intense at night after performing exercises and nor- patient externally rotated her lower extremities, a naturalmal activity at school. She had not returned to dance but position for dancers, and demonstrated genu valgus dur-had returned to teaching 3 childrens dance classes which ing exercises. She also complained of pain with single legwere 30 minutes in duration within the past week. She exercises. When cued to maintain her foot in a neutralperformed her HEP every other day since examination position with correct lower quarter alignment, the patientand described the pain as intense and achy after the exer- reported decreased knee pain during therapeutic exercis-cises. es, especially with single leg exercises.The treatment focus was on simple strengthening exercis-es for hip and core muscles necessary for activities of daily Table 2. Follow up visit 1 exercises performed in clinic. Figure 1. Unilateral leg press with elastic tubing. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 89
  • 6. Figure 4. Cable cord bilateral squatFigure 2. Monster walk with with upper extremity row with elasticelastic tubing around distal thigh. tubing and abduction resistance.Figure 3. Prone push up position withknee to chest at neutral and lateral andmedial angles with lower extremity move-ment. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 90
  • 7. Follow-up Visit 2AssessmentUpon return to treatment a week later the patient had min- decrease severe genu valgus collapse due to lack ofimal to no pain at rest or with activity with most intense strength of abductor and external rotator muscles. Thepain measured at a 2/10 on VAS. She had not increased her patient complained of fatigue and cramping in stabilizingactivity but was able to ascend and descend stairs at school. hip during exercises performed with foot in neutral hipUpon reassessment for strength the patient demonstrated rotation position. The patient was able to climb stairs with-better structural alignment of the lower quarter with out any pain and had no reports of knee pain during treat-demonstration of bilateral squat and unilateral squat and a ment. The patient was instructed to use elastic tubing dur-decrease in pain during performance of each. She contin- ing HEP for proper recruitment of abductor and externalued to demonstrate a genu valgus collapse with unilateral rotator muscles and their ability to decrease vector forcessquat. on anterior/medial knee during closed chain activities. She continued HEP performance every other day duringDue to a decrease in overall pain intensity with exercise, the week between treatments. HEP was expanded tothe treatment focus was progressed to functional include diagonal hops and single leg squats with ER of hipmovements with strengthening to mimic simple dance during squat and IR of hip with rising.maneuvers. Elastic tubing was utilized for hip abductormuscle resistance during all single leg hip exercises to Table 3. Follow up visit 2 exercises performed in clinic.Figure 5. Unilateral leg press with circle board. Figure 6. Forward step ups. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 91
  • 8. Figure 7. Single leg squat with internal rotation (IR) of hip concentric motion and eternal rotation (ER) of hip with eccentric motion.North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 92
  • 9. Follow-up Visit 3AssessmentUpon return to therapy a week later the patient reported improved abduction/ER strength during sagittal planehaving had no pain in her knee all week during ADLs but activities by demonstrating decreased valgus collapsethat she had not returned to dance class. She did contin- with unilateral squatting. The patient continued to lackue to teach a childrens class, which only required very proper control in coronal plane activities and movementsimple dance moves, all of which were pain free. She no with complaints of fatigue in hips. Over the next weeklonger used the elevator at school and could ascend and the patient was allowed to return to tap class and joggingdescend stairs without pain. on pavement 1-2 miles a day. These activities were fol- lowed with return to ballet and contemporary danceDue to the patients report of no pain all week, treatment class the following week. She returned to therapy afterexercises were advanced to mimic dance moves with two weeks. Her HEP was advanced to include themultiple planes and involvement of upper and lower complex activities she had performed during in-clinicextremities in a sport specific preparation for return to treatment.dancing. During treatment the patient demonstrated Table 4. Follow up visit 3 exercises performed in clinic. Figure 8. Side planks with knees flexed and single leg Figure 9. Crabwalk with squat and abduction of top leg. elastic tubing around distal thigh. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 93
  • 10. Follow-up Visit 4AssessmentThe patient reported a return to dance class 4 days a week strated proper form with jumps and no compensations.for about 8 hours a week at 80% of pre-injury levels. She Following pre-treatment re-examination the patient had noreported only minimal pain during ballet class with certain complaints of pain or fatigue with treatment exercises. Themoves that required excessive external rotation. The HEP was advanced to focus on unilateral squats, jumps,patient was able run pain free on a treadmill for 2 miles for and hops in an externally rotated position for return towarm-up. For re-examination prior to treatment the patient sport training. The patient was to increase dance classperformed bilateral jumps and unilateral hops on even and hours and intensity and return to therapy in two weeks foruneven surfaces to assess power and distance. She demon- discharge. Table 5. Follow up visit 4 exercises performed in clinic. Follow-up Visit 5AssessmentUpon return to therapy two weeks later the patient tive 40-yard dashes at maximum speed and performedreported being 100% better. She returned to dance 5 days a repetitive jumping and skipping for 40 yards each. All activ-week for 9-10 hrs a week at 100% pre-injury level. She also ities performed on pavement, with no reports of pain withreported jogging 3 miles twice a week on off dance days. either activity.Prior to physical therapy she could only perform one pirou-ette however now was able to perform three in succession.After re-examination for discharge the patient ran consecu- Table 6. Follow up visit 5 exercises performed in clinic. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 94
  • 11. OUTCOMES strength and 26% less hip abductor muscle strength thanAt the discharge examination all hip and knee manual mus- control subjects.10 Bogla et al35 also showed similar resultscle tests were graded as 5/5. Overall pain level was a 0/10 for subjects with PFPS, who demonstrated 24% less hipon VAS with all activities of daily living, school require- external rotator muscle strength and 26% less hip abductorments, ascending and descending stairs, as well as with muscle strength than controls. These studies support thedancing. The patient scored a 74/80 on the Lower theory that hip abductor and hip external rotator muscleExtremity Functional Scale and an 8.7/10 on the PSFS. The weakness may allow excessive hip adduction and hip inter-one exception was a 1/10 pain on VAS, which the patient nal rotation during activity, thus contributing todescribed with certain ballet pliés and turnouts that patellofemoral joint stress.10,34,36 More importantly, severalrequired maximal external rotation on both extremities. authors have reported favorable outcomes in patients whoThis limitation did not limit her performance in ballet participated in a rehabilitation program targeting the hipclass. She reported gradually increasing the amount of time musculature for the treatment of anterior knee pain.34, 37, 38she spent dancing each week, but was able to perform at Authors have reported that female athletes land with less100% of pre-injury level while in class. She was perform- knee flexion, less time to peak knee flexion, greater kneeing and teaching dance class 5 days a week for up to 10-12 valgus, greater vertical ground reaction forces, and lesshours a week at time of discharge. hamstring activation than male athletes which may lead to ACL injury.39 Jumping and landing is an integral part ofDISCUSSION dance. Lephart et al,6,11 suggested that the neuromuscularWeakness of the hip abductor and external rotator muscle characteristics of the lower extremity in female athletesmay be associated with poor eccentric control of femoral can be improved with a basic exercise program of jumpsadduction and internal rotation during weight-bearing and single leg stance exercises which may reduce the riskactivities. This lack of control can contribute to malalign- for injury. A reduction in injury rate after a strength-train-ment of the patellofemoral joint as the femur medially ing program alone was reported in those after ACL injury.6rotates under the patella.30,31 To reduce excessive lateral Elevated neuromuscular control may account for some ofpatellar deviations during weight-bearing activities and the strength gains.40 Improvements in a muscles ability topotentially reduce anterior knee pain, physical therapy generate force, appears to be a way for dancers to enhanceintervention was necessary to address hip muscle perform- their performance.1 The dancer presented in this caseance and control of the LE during activity.32,33 Decreased study demonstrated significant functional improvementship stability due to muscular weakness, especially that of as reflected by the LEFS and PSFS scores with a primarythe gluteus medius and external rotator muscles, may intervention of strengthening. An awareness of these fac-affect the patellofemoral joint position in some patients.5 tors will assist dancers to improve training techniques andDecreased hip abductor and hip external rotation muscle to employ effective injury prevention strategies.strength may allow the pelvis to collapse under the weightof the body during single-leg stance which is a common CONCLUSIONmaneuver in dance. When a dancer drops their hip, a val- This case report outlines rehabilitation guidelines, agus stress at the knee can occur and that may aggravate a therapeutic exercise program, functional training interven-patellofemoral joint condition.5,17 tions, and outcomes utilized with a female dancer withRobinson and Nee34 demonstrated that females between 12 PFPS. The patient achieved a successful outcome, return-and 35 years of age, presenting with unilateral PFPS ing to full participation of dance training and employmentdemonstrate significant impairments in the isometric as a dance instructor. Critical to this case was implement-strength of their symptomatic limbs for hip abduction, ing concepts associated with regional interdependence.extension, and external rotation when compared to unin- Proximal weakness through the core and hip region of thisjured control subjects. Additional researchers have shown female dancer likely contributed to deficits in neuromuscu-that young females with PFPS demonstrate hip abduction lar control of the lower extremity kinetic chain duringand external rotation muscle weakness when compared to squatting, jumping, and hopping. Clinicians should consid-that of age-matched non-symptomatic females.10 Subjects er the influence of proximal impairments when examiningwith PFPS demonstrated 36% less external rotation muscle and treating a patient with dysfunction of the lower limb. North American Journal of Sports Physical Therapy | Volume 5, Number 2 | June 2010 | Page 95
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