The influence of a depressed scapular alignment on upper limb neural tissue mechanosensitivity and local pressure pain sensitivity.
A depressed scapular alignment could lead to prolonged and repetitive stress or compression of the brachial plexus, resulting in sensitization of neural tissue. However, no study has investigated the influence of alignment of the scapulae on sensitization of upper limb neural tissue in otherwise asymptomatic people. In this case-control study, we investigate the influence of a depressed scapular alignment on mechanosensitivity of the upper limb peripheral nervous system as well as pressure pain thresholds (PPT).



Asymptomatic individuals with neutral vertical scapular alignment (n = 25) or depressed scapular alignment (n = 25) participated. We measured the upper limb neurodynamic test (ULNT1), including assessment of symptom response and elbow range of motion (ROM), and PPT measured over upper limb peripheral nerve trunks, the upper trapezius muscle and overlying cervical zygapophyseal joints.



Subjects with a depressed scapular reported significantly greater pain intensity (t = 5.7, p < 0.0001) and reduced elbow extension ROM (t = -2.7, p < 0.01) during the ULNT1 compared to those with a normal scapular orientation. Regardless of the location tested, the group presenting with a depressed scapular had significantly lower PPT compared to those with a normal scapular orientation (PPT averaged across all sites: normal orientation: 3.3 ± 0.6 kg/cm2, depressed scapular: 2.1 ± 0.5 kg/cm2, p < 0.00001).



Despite being asymptomatic, people with a depressed scapular have greater neck and upper limb neural tissue mechanosensitivity when compared to people with a normal scapular orientation. This study offers insight into the potential development of neck-arm pain due to a depressed scapular position.
Physiotherapy Department, Faculty of Health, Exercise and Sport, European University, Villaviciosa de Odón, Madrid, Spain.
Patricia
P
Martínez-Merinero
Department of Physical Therapy, University of Valencia, Valencia, Spain.
Enriqe
E
Lluch
Physical Therapy Department, University of Alcalá, Alcalá de Henares, Madrid, Spain.
Tomas
T
Gallezo-Izquierdo
Physical Therapy Department, University of Alcalá, Alcalá de Henares, Madrid, Spain.
Daniel
D
Pecos-Martín
Rehabilitation and Physical Medicine Department, Medical Hydrology, Complutense University of Madrid, Madrid, Spain.
Gustavo
G
Plaza-Manzano
Physical Therapy Department, University of Alcalá, Alcalá de Henares, Madrid, Spain.
Susana
S
Nuñez-Nagy
Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK. Electronic address: d.falla@bham.ac.uk.
Deborah
D
Falla
D000328:Adult; D016022:Case-Control Studies; D003877:Dermatitis, Contact / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D058748:Pain Perception / Q000502:physiology*; D011312:Pressure; D016059:Range of Motion, Articular / Q000502:physiology*; D012540:Scapula / Q000166:cytology* / Q000293:injuries*; D034941:Upper Extremity / Q000503:physiopathology*; D055815:Young Adult
Cervical spine; Neurodynamics; Scapula