Affiliations: [a] Department of Physical Therapy, The Graduate School,
Inje University, Gimhae, Korea | [b] Department of Physical Therapy, Nambu University,
Kwangju, Korea | [c] Department of Physical Therapy, College of Biomedical
Science and Engineering, Inje University, Gimhae, Korea
Correspondence:
[*]
Corresponding author: Jae-Seop Oh, Department of Physical
Therapy, College of Biomedical Science and Engineering, Inje University, 607
Obang-Dong, Gimhae-Si, Gyeongsangnam-Do, 621-740, Korea. Tel.: +82 55 320 3679;
Fax: +82 55 329 1678; E-mail: [email protected].
Abstract: BACKGROUND: Although strength exercises for shoulder girdle
protraction (SGP) have been emphasized in subjects with scapular winging, few
experimental studies have SGP strength measured this function in this cohort. OBJECTIVE: To compare SGP strength and performance of the upper
quarter closed-kinetic-chain in healthy subjects and patients with scapular
winging. METHODS: Twenty-six men (13 patients with scapular winging,
13 controls) exerted maximal isometric SGP force against a force-measurement
device while the upper quarter Y-balance test was conducted to examine the
performance of the upper quarter closed-kinetic-chain using a Y-balance kit. RESULTS: The SGP strength in the patient group was significantly lower
than that of the control group (p=0.001) while the scores on the Y-balance
did not differ between the groups. The correlation between strength and motion
of the upper limb during performance of upper quarter closed-kinetic-chain was
relatively low (r=0.394, p=0.046). A sensitivity analysis has indicated
that based on the extreme values of the patient group (the maximal individual
SGP strength score) and the control group (the minimal individual strength
score), 4 of the patients and 8 of the healthy participants, would have been
categorized as uninvolved (false negatives) and involved (false positives),
respectively. However based on the mean SGP strength score, only one patient
crossed into the control subjects distribution while none of the control
subject have crossed into the patients distribution. CONCLUSIONS: These findings indicate that although scapular winging may be associated with
SGP weakness, particularly in cases where the isometric force is less than
130 N. However, great care has to be taken in interpretation of findings while
further research should be encouraged.
Keywords: Scapular alignment, SGP strength, upper quarter Y-balance test
