Ogura Dantas L.1, Leao Ribeiro I.1, Rezende Camargo P.1, Viana Ferrari A.1, Alburquerque Sendin F.2, Fatima Salvini T.1
1Federal University of São Carlos - UFSCar, Physical Therapy Department, São Carlos, Brazil, 2University of Cordoba, Nuclear Medicine and Rehabilitation Department, Cordoba, Spain
Background: Surgical treatment for breast cancer as axillary lymph node dissection (ALND) and sentinel node biopsy (SNB) followed by breast conserving and removing surgery can cause upper limb impairments. The surgical residual effects can affect shoulder and arm mobility and probably reduce the functional use of upper extremity. Altered scapular kinematics is presented in this population, but there is a lack of studies investigating the late effects of breast cancer surgery on scapular kinematics.
Purpose: To analyze shoulder function (shoulder range of motion, ROM and muscles strength) and to assess scapular kinematics in women who undergone breast cancer surgery. Our hypothesis was that surgery group presents functional impairments related to biomechanics in comparison to a control group.
Methods: Twenty-one women were included on surgery group (age: 50.2±9.8 years; body mass index: 25.3±2.7kg/m²; period of surgery: 24.2±20.5 months; procedures: mastectomy (n=14), quadrantectomy (n=07), ALND (n=12) and SNB (n=09)). Control group was matched to surgical group related to age and body mass index (age: 50.7±10.1 years; body mass index: 24.4±2.8kg/m²). Three-dimensional kinematics of the scapula were evaluated during arm elevation in the scapular plane of movement with the Flock of Birds® system. Shoulder range of motion (abduction, flexion, external and internal rotation movements) was assessed by a digital inclinometer and muscle strength (abduction and external rotation movements) by a hand held dynamometer. Data were analyzed with ANOVA two-way for repeated measures (for kinematics results), Man Whitney test (range of motion and muscle strength results), independent T, chi square, fischer tests (for other variables). Effect size was assessed with Cohens d coefficient for all quantitative variables. A significance level of 5% was adopted.
Results: Both groups were similar at demographic characteristics (P>0.05) and surgery group did not have differences related to surgical procedure (P>0.025 for all types of surgery). Shoulder function was poor at surgery group related to ROM (external rotation, P 0.025 and Cohens d >1.00, mean difference of approximately 10 degrees comparing affected side to non-affected and 14 degrees when compared to control group); external rotation muscle strength: affected side (5.29±1.81Kg), non-affected side (5.96±1.59Kg), control group (7.70±1.03Kg), P 0.025 and Cohens d >1.00, comparing affected side to control group; abduction muscle strength: affected side (6.70±2.18Kg), non-affected side (7.57±2.23Kg), control group (10.53±1.97Kg), P 0.025 and Cohens d >1.00, comparing groups. Scapular kinematics was lower at upward rotation during arm elevation for surgery group, with interaction angle x side (P=0.022; F=2.572). Surgery group revealed a difference of 7.2 degrees of movement comparing affected and control group; Cohen d coefficient was -0.88.
Conclusion(s): Surgical treatment for breast cancer may affect upper limb biomechanics. There is evidence for lower shoulder ROM, muscle strength and lower superior rotation of the scapula during elevation movement, even after many years of the surgical treatment.
Implications: Early intervention of physical therapy after breast cancer surgery can prevent the emergence of biomechanical changes of the upper limb.
Funding acknowledgements: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and grant #2011/22122-5, São Paulo Research Foundation (FAPESP)
Topic: Musculoskeletal: upper limb
Ethics approval: Ethics Committee on Human Research from Federal University of São Carlos (protocol number 874.181/2014)
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