Vol. 3, No 1, 2005 pp. 93 - 105
UDC 796.332.015.2:616.747
Scientific Paper
MUSCLE ACTIVITY OF SHOULDER JOINTS IN
PATIENTS WITH MULTIDIRECTIONAL SHOULDER
INSTABILITY DURING PULL, FORWARD PUNCH, ELEVATION AND OVERHEAD THROW
Árpád Illyés1, Rita M. Kiss2
1Semmelweis University Orthopaedic
Department, Budapest, Hungary
E-mail: illyes_arpad@yahoo.com
2Academic Research Group of
Structures,
Budapest, Hungary
E-mail: kissrit@t-online.hu
Abstract. Multidirectional shoulder joint instability alters the
role of dynamic stabilizers, as a result of which the motion patterns
of
muscles surrounding the shoulder joint are also changed. The aim of
this
study was to compare the muscle activity of patients with
multidirectional
shoulder instability and the control group during pull, forward punch
and
elevation and during overhead throw. Fifteen subjects with
multidirectional
shoulder instability and fifteen control subjects with normal, healthy
shoulders participated in the study. Both shoulders were tested in all
subjects. Signals were recorded by surface EMG from eight different
muscles
during pull, forward punch, elevation and overhead throw. The maximum
values
of normalized voluntary electrical activity, and the time span among
peak
muscle electrical activities in percent of total time of a movement
cycle
were compared with those of the healthy control group. Test results
suggest
that in the case of patients with multidirectional shoulder instability
the different motions are performed in a different way. The results
give
rise to the assumption that the organism will attempt to ensure
centralization
of the glenohumeral joint and the reduction of instability is attempted
to be ensured by the organism through increasing the role of rotator
cuff
muscles and decreasing the role of m. deltoideus, m. biceps brachii,
and
m. pectoralis maior. The analysis of time span shows that in the case
of
patients with multidirectional shoulder instability, the time
difference
between the peaks of normalized voluntary electrical activity of the
patients
is significantly greater than those of the control group. It can be
established
that the neuromuscular control and proprioception of patients with
multidirectional
shoulder instability differ from those of the control group.
Key words: shoulder joint, multidirectional instability,
electromyography, motion pattern.
MIŠIĆNA AKTIVNOST RAMENIH ZGLOBOVA KOD
PACIJENATA SA VIŠESMERNOM RAMENOM
NESTABILNOŠĆU TOKOM VUČENJA, UDARACA UNAPRED, PODIZANJA I BACANJA PREKO
GLAVE
Višesmerna nestabilnost ramenih zglobova menja ulogu dinamičnih
stabilizatora,
a kao rezultati će se javiti promene u obrascu kretanja mišića koji
okružuju
ramene zglobove. Cilj ove studije jeste da se uporedi mišićna aktivnost
pacijenata sa višesmernom ramenom nestabilnošću i kontrolne grupe tokom
vučenja, udaraca unapred, podizanja i bacanja preko glave. 15 subjekata
sa višesmernom ramenom nestabilnošću i 15 kontolnih subjekata sa
normalnim,
zdravim ramenima su učestvovali u studiji. Oba ramena bila su testirana
kod svih subjekata. Signali osam različitih mišića tokom vučenja,
udaraca
unapred, podizanja i bacanja preko glave beleženi su na površini EMG-a.
Maksimalne vrednosti normalizovane dobrovoljne električne aktivnosti u
vremenskom intervalu između maksimalne mišićne električne aktivnosti u
procentima celokupnog vremena ciklusa kretanja, su upoređeni sa
podacima
zdrave kontrolne grupe. Rezultati testa pokazuju da u slučaju
pacijenata
sa višesmernom ramenom nestabilnošću različiti pokreti se izvode na
različite
načine. Rezultati otvaraju pretpostavku da će organizam pokušati da
obezbedi
centralizaciju glenohumeralnih zglobova i da smanji nestabilnost
povećanjem
uloge rotirajućih mišića i smanjenjem uloge m. deltoideus, m. biceps
brachii
i m. pectoralis major. Analiza vremenskog intervala pokazuje da je kod
pacijenata sa višesmernom ramenom nestabilnošću, vremenska razlika
između
vrhova normalizovane dobrovoljne električne aktivnosti značajno veća
nego
vrhova kontrolne grupe. Može biti utvrđeno da se neuromišićna kontrola
i propriocepcija pacijenata sa višesmernom ramenom nestabilnošću
razlikuje
od rezultata kontrolne grupe.
Ključne reči: rameni zglob, višesmerna nestabilnost,
elektromiografija,
obrazac kretanja.
