Digitizing bony landmarks is a common technique used to measure scapular position, but it has not been validated against a gold standard. The aim of this study was to determine the accuracy of this technique for four physiological arm movements using optoelectronic markers mounted on scapular bone pins as a gold standard. Eight subjects had bone pins inserted into their lateral scapular spine. Three points were digitized on the scapula with an optoelectronic probe: the medial root of the scapular spine, the posterolateral corner of the acromion, and the inferior angle of the scapula. The four active movements tested in this study were glenohumeral abduction, glenohumeral horizontal adduction, hand behind back, and forward reaching. The three bony landmarks were digitized six times in three different positions for each movement. Data from one subject were rejected secondary to pin loosening. The overall position-specific r.m.s. errors ranged from 2.0° to 12.5°. The full abduction position had considerably higher r.m.s. errors than the other positions (posterior tipping, 12.5°; upward rotation, 7.3°; internal rotation, 12.0°). It appears that the digitization of bony landmarks may be a valid method for measuring changes in scapular attitude with the following caveats: the full abduction position has a high r.m.s. error, and small scapular motions have high percentage errors.
de GrootJ. H.van WoenselW.van der HelmF. C.‘Effect of different arm loads on the position of the scapula in abduction postures.’Clin. Biomechanics14 (5) (1999): 309–314
2.
PascoalA. G.van der HelmF. F.Pezarat CorreiaP.CaritaI.‘Effects of different arm external loads on the scapulo-humeral rhythm.’Clin. Biomechanics15 (Suppl. 1) (2000): S21-S24.
3.
de GrootJ. H.‘The scapulo-humeral rhythm: Effects of 2-D roentgen projection.’Clin. Biomechanics14 (1) (1999): 63–68
4.
LudewigP. M.CookT. M.NawoczenskiD. A.‘Three-dimensional scapular orientation and muscle activity at selected positions of humeral elevation.’J Orthop. Sports Phys. Therapy24 (2) (1996): 57–65
5.
HebertL. J.MoffetH.McFadyenB. J.DionneC. E.‘Scapular behavior in shoulder impingement syndrome.’Arch. Phys. Medicine Rehabil.83 (1) (2002): 60–69
6.
LukasiewiczA. C.McClureP.MichenerL.PrattN.SennettB.‘Comparison of 3-dimensional scapular position and orientation between subjects with and without shoulder impingement.’J. Orthop. Sports Phys. Therapy29 (10) (1999): 574–583 discussion, 584–576
7.
van der HelmF. C.PronkG. M.‘Three-dimensional recording and description of motions of the shoulder mechanism.’Trans. ASME, J. Biomech. Engng117 (1) (1995): 27–40
8.
MeskersC. G.VermeulenH. M.de GrootJ. H.van Der HelmF. C.RozingP. M.‘3D shoulder position measurements using a six-degree-of-freedom electromagnetic tracking device.’Clin. Biomechanics13 (4–5) (1998): 280–292
9.
BarnettN. D.DuncanR. D.JohnsonG. R.‘The measurement of three dimensional scapulohumeral kinematics — a study of reliability.’Clin. Biomechanics14 (4) (1999): 287–290
10.
HebertL. J.MoffetH.McFadyenB. J.St-VincentG.‘A method of measuring three-dimensional scapular attitudes using the optotrak probing system.’Clin. Biomechanics15 (1) (2000): 1–8
11.
Della CroceU.LeardiniA.ChiariL.CappozzoA.‘Human movement analysis using stereophotogrammetry. Part 4: Assessment of anatomical landmark misplacement and its effects on joint kinematics.’Gait Posture21 (2) (2005): 226–237
12.
BourneD. A.ChooA. M.ReganW. D.MacIntyreD. L.OxlandT. R.‘Three-dimensional rotation of the scapula during functional movements: An in vivo study in healthy volunteers.’J. Shoulder Elbow Surg.16 (2) (2007): 150–162
13.
BourneD.Accuracy and reliability of a new method of measuring three-dimensional scapular kinematics MSc Thesis, University of British Columbia, Vancouver, British Columbia, Canada, 2003.
14.
WuG.van der HelmF. C.VeegerH. E.MakhsousM.Van RoyP.AnglinC.NagelsJ.KardunaA. R.McQuadeK.WangX.WernerF. W.BuchholzB.‘ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion — Part II: Shoulder, elbow, wrist and hand.’J. Biomechanics38 (5) (2005): 981–992
15.
KardunaA. R.McClureP. W.MichenerL. A.SennettB.‘Dynamic measurements of three-dimensional scapular kinematics: A validation study.’Trans. ASME, J. Biomech. Engng123 (2) (2001): 184–190
16.
KardunaA. R.McClureP. W.MichenerL. A.‘Scapular kinematics: Effects of altering the Euler angle sequence of rotations.’J. Biomechanics33 (9) (2000): 1063–1068
17.
SoderkvistI.WedinP. A.‘Determining the movements of the skeleton using well-configured markers.’J. Biomechanics26 (12) (1993): 1473–1477
18.
McQuadeK. J.Hwa WeiS.SmidtG. L.‘Effects of local muscle fatigue on three-dimensional scapulohumeral rhythm.’Clin. Biomechanics10 (3) (1995): 144–148
19.
FullerJ.LiuL. J.MurphyM. C.MannR. W.‘A comparison of lower-extremity skeletal kinematics measured using skin- and pin-mounted markers.’Human Movement Sci.16 (2–3) (1997): 219–242
20.
GregersenG. G.LucasD. B.‘An in vivo study of the axial rotation of the human thoracolumbar spine.’J. Bone Jt Surg. Am.49 (2) (1967): 247–262
21.
GunzburgR.HuttonW.FraserR.‘Axial rotation of the lumbar spine and the effect of flexion. An in vitro and in vivo biomechanical study.’Spine16 (1) (1991): 22–28
22.
HarrymanD. T.SidlesJ. A.HarrisS.MatsenF. A.III‘Laxity of the normal glenohumeral joint: A quantitative in vivo assessment.’J. Shoulder Elbow Surg.1 (1992): 66–76
23.
KohT. J.GrabinerM. D.BremsJ. J.‘Three-dimensional in vivo kinematics of the shoulder during humeral elevation.’J. Appl. Biomechanics14 (3) (1998): 312–326
24.
LumsdenR. M.MorrisJ. M.‘An in vivo study of axial rotation and immobilization at the lumbosacral joint.’J. Bone Jt Surg Am.50 (8) (1968): 1591–1602
25.
NeptuneR. R.HullM. L.‘Accuracy assessment of methods for determining hip movement in seated cycling.’J. Biomechanics28 (4) (1995): 423–437
26.
ReinschmidtC.van den BogertA. J.LundbergA.‘Tibiofemoral and tibiocalcaneal motion during walking: External vs. skeletal markers.’Gait Posture6 (2) (1997): 98–109
27.
ReinschmidtC.van den BogertA. J.MurphyN.‘Tibiocalcaneal motion during running, measured with external and bone markers.’Clin. Biomechanics12 (1) (1997): 8–16
28.
ReinschmidtC.van den BogertA. J.NiggB. M.‘Effect of skin movement on the analysis of skeletal knee joint motion during running.’J. Biomechanics30 (7) (1997): 729–732
29.
SteffenT.RubinR. K.BaramkiH. G.AntoniouJ.MarchesiD.AebiM.‘A new technique for measuring lumbar segmental motion in vivo. Method, accuracy, and preliminary results.’Spine22 (2) (1997): 156–166
30.
MyersJ.JollyJ.NagaiT.LephartS.‘Reliability and precision of in vivo scapular kinematic measurements using an electromagnetic tracking device.’J. Sport Rehabil.15 (2) (2006): 125–143
31.
LudewigP. M.CookT. M.‘Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement.’Phys. Therapy80 (3) (2000): 276–291
