and impact experienced in running on land. 7 However, participants need to overcome water resistance and turbulence in an unstable floating environment. 8 Therefore, it is reasonable to query to what extent trunk muscle activation to stabilize the body during DWR differs from that needed on land. 9
Billy Chun-Lung So, Calvin Hong-Nin Yuen, Ken Long-Hin Tung, Sheena Lam, Sammy Lan Cheng, Zina Wing-Lam Hung, Rainy Wai-Kwan Leung and Grace Pui-Yuk Szeto
Ece Acar, Tamer Çankaya and Serkan Öner
stability area and a lower sway area are the indicators of a stable balance. Trunk muscles have important functions in balance and mobility and give a stable ground for the extremities by providing postural support and stability to the spine ( Hodges et al., 2003 ; Hodges & Richardson, 1997 ; Suri, Kiely
Kunal Bhanot, Navpreet Kaur, Lori Thein Brody, Jennifer Bridges, David C. Berry and Joshua J. Ode
reach directions (anterior, medial, and posteromedial) of the SEBT. 22 These authors did not use the commonly used directions (anterior, posteromedial, and posterolateral) of the SEBT. No study has measured the hip muscle activity in the other 5 directions of the SEBT and trunk muscle activity in all
Rasool Bagheri, Ismail Ebrahimi Takamjani, Mohammad R. Pourahmadi, Elham Jannati, Sayyed H. Fazeli, Rozita Hedayati and Mahmood Akbari
, 14 Other factors such as disability, duration of LBP, and altered motor control of trunk muscle were suggested to be responsible for this adaptive gait pattern. 7 , 15 , 16 Muscle endurance is defined as the ability of a muscle or group of muscles to maintain a fixed contraction or repeatedly
Geetanjali Gera, Kelsey E. McGlade, Darcy S. Reisman and John Peter Scholz
In this study, we investigated deficits in coordination of trunk muscle modes involved in the stabilization of the trunk’s trajectory for reaching upward and downward beyond functional arm length. Trunk muscle activity from 10 stroke survivors (8 men, 2 women; 64.1 ± 10.5 years old) and 9 healthy control subjects (7 men, 2 women; 59.3 ± 9.3 years old) was analyzed. Coordination of trunk muscle modes to stabilize the trunk trajectory was investigated using the uncontrolled manifold (UCM) analysis. The UCM analysis decomposes the variability of muscle modes into good and bad variability. The good variability does not affect the control of trunk motion, whereas the bad variability does. In stroke survivors, deficits in the ability to flexibly combine trunk muscle modes was associated with reduced ability to minimize those combinations of trunk muscle modes that led to an error in trunk trajectory (bad variability), and this had a greater effect on reaching upward. This reduced coordination of trunk muscle modes during reaching was correlated with a clinical measure of trunk impairment.
Ozgur Surenkok, Ayse Kin-Isler, Aydan Aytar and Zuhal Gültekin
This study sought to determine the effects of trunk-muscle fatigue and blood lactic acid elevation on static and dynamic balance.
Fatigue was induced by an isokinetic protocol, and static and dynamic balance were assessed during bilateral stance using a Kinesthetic Ability Trainer. Subjects participated in a fatigue protocol in which continuous concentric movements at 60°/s were performed until the torque output for both trunk flexion and extension dropped below 25% of the calculated peak torque for 3 consecutive movements.
Before and immediately after the fatigue protocol, blood lactic acid measurements and static- and dynamic-balance measurements were recorded.
An increase in lactic acid levels was detected in all subjects. According to a dependent-samples t test, significant differences in balance and lactic acid values were found after the fatigue protocol. There was no correlation between lactic acid accumulation (change between prefatigue and postfatigue levels) and balance-score differences.
Trunk-muscle fatigue has an adverse effect on static and dynamic balance.
Anand Navalgund, John A. Buford, Mathew S. Briggs and Deborah L. Givens
Altered trunk muscle reflexes have been observed in patients with low back pain (LBP). Altered reflexes may contribute to impaired postural control, and possibly recurrence of LBP. Specific stabilization exercise (SSE) programs have been shown to decrease the risk of LBP recurrence in a select group of patients with acute, first episode LBP. It is not known if trunk muscle reflex responses improve with resolution of subacute, recurrent LBP when treated with a SSE program. A perturbation test was used to compare trunk muscle reflexes in patients with subacute, recurrent LBP, before and after 10 weeks of a SSE program and a group of matched control subjects (CNTL). The LBP group pre therapy had delayed trunk muscle reflexes compared with the CNTL group. Post therapy reflex latencies remained delayed, but amplitudes increased. Increased reflex amplitudes could limit excessive movement of the spine when perturbed; potentially helping prevent recurrence.
Urs Granacher, Andre Lacroix, Katrin Roettger, Albert Gollhofer and Thomas Muehlbauer
This study investigated associations between variables of trunk muscle strength (TMS), spinal mobility, and balance in seniors. Thirty-four seniors (sex: 18 female, 16 male; age: 70 ± 4 years; activity level: 13 ± 7 hr/week) were tested for maximal isometric strength (MIS) of the trunk extensors, flexors, lateral flexors, rotators, spinal mobility, and steady-state, reactive, and proactive balance. Significant correlations were detected between all measures of TMS and static steady-state balance (r = .43−.57, p < .05). Significant correlations were observed between specific measures of TMS and dynamic steady-state balance (r = .42−.55, p < .05). No significant correlations were found between all variables of TMS and reactive/proactive balance and between all variables of spinal mobility and balance. Regression analyses revealed that TMS explains between 1–33% of total variance of the respective balance parameters. Findings indicate that TMS is related to measures of steady-state balance which may imply that TMS promoting exercises should be integrated in strength training for seniors.
Paul F. Greene, Christopher J. Durall and Thomas W. Kernozek
A torso-elevated side support (TESS) has previously been described for measuring endurance of the lateral trunk muscles. In some individuals, however, TESS performance may be hindered by upper extremity pain or fatigue. For this reason a novel test, the feet-elevated side-support test (FESS), was examined.
To determine intersession reliability of a FESS and a TESS on the left and right sides using a single examiner, to evaluate the relationship between tests, and to compare reasons for test termination.
Nonexperimental prospective repeated measures.
A convenience sample of 60 healthy participants from a university community (17 men, 43 women; age 21.1 ± 2.2 y; height 169.9 ± 9.5 cm; weight 67.1 ± 11.9 kg).
Intraclass correlation coefficient between 3 testing sessions = .87 with right FESS, .86 with left FESS, .78 with right TESS, and .91 with left TESS. Pearson correlation coefficients ranged from .59 (between left FESS and left TESS in women) to .75 (between left FESS and left TESS in men). Upper extremity pain or fatigue was the reason given for test termination in 42.5% of participants during the TESS and 5.0% during the FESS (P = .000, Fisher exact test).
FESS and TESS had comparable intersession reliability by the same evaluator. Moderate to high correlations were found between FESS and TESS scores, suggesting that the tests assess similar qualities. Far fewer participants terminated the FESS because of upper extremity pain or fatigue. Thus, the FESS may be a suitable alternative to the previously validated TESS, particularly for individuals with upper extremity pain or weakness.
Chi-Whan Choi, Jung-Wan Koo and Yeon-Gyu Jeong
(psoas, quadratus lumborum, abdominal wall) in the lumbar spine . J Biomech . 1996 ; 29 ( 11 ): 1503 – 1507 . PubMed ID: 8894932 doi: 10.1016/0021-9290(96)84547-7 8894932 16. Vera-Garcia FJ , Moreside JM , McGill SM . MVC techniques to normalize trunk muscle EMG in healthy women . J