Affiliations: [a] Department of Physical Therapy, Inje University, Gimhae, Korea | [b] Department of Rehabilitation Science, Graduate School, Inje University, Gimhae, Korea | [c] Department of Occupational Therapy, Dongseo University, Busan, 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: ysrehab@inje.ac.kr
Abstract:
OBJECTIVE: This study examined the effect of modified prone trunk-extension (PTE)
exercises on selective activity of the thoracic erector spinae. METHODS: Thirty-nine healthy subjects performed four modified PTE exercises,
involving location of the edge of the table (iliac crests [IC] vs. xiphoid
process [XP]) and the degree of trunk extension (horizontal vs.
hyperextension). Electromyography signals were collected bilaterally from
the longissimus thoracis (LT), iliocostalis thoracis (ICT), and iliocostalis
lumborum (ICL). Normalized LT:ICL and ICT:ICL ratios were calculated. The
data were analyzed using a repeated measures two-way analysis of variance. RESULTS: The LT:ICL and ICT:ICL ratios were significantly higher under the XP than
the IC condition (p < 0.05); however, the degree of trunk extension did not
affect the ratio (p > 0.05). Activity in the lumbar erector spinae and left
ICT muscles was greater when subjects were in the hyperextended position
than in the horizontal position. Moreover, activity in the thoracic erector
spinae was greater when the table edge was aligned with the IC compared with
the XP (p < 0.05). CONCLUSIONS: Our findings suggest that PTE exercise with the XP aligned with the table
edge increased the selective activation of the thoracic erector spinae
muscles.
