Evidence of Benefit of Transverse Abdominus Training Alone or in Combination with Pelvic Floor Muscle Training to Treat Female UI: A Systematic Review.

Introduction:

PFMT is recommended for first line of treatment of SUI and Mixed UI (50 RCTs). Due to synergistic activity between TrA and PFM with normal trunk activities, it is theorized that one can train TrA to enhance PFMT. The authors reviewed journal publications to find evidence to support TrA training alone or in combination with PFMT for treatment of SUI and mixed UI in women to determine if current clinical practice should be replaced  with new model or if current practice should change.

Sapsford et al dispute several issues in this study via a letter to the editor. Their comments are listed in bold.

Method:

Hand and computer search of published references for PFM and Abdominals and pelvic floor and TRA and deep abdominals. Key researchers in the area were contacted.

  

Results: 4 questions were asked:

1) Is there evidence to support hypothesis that there is a co contraction of TrA with instruction of PFM contraction?

Yes... The authors reference a study by Madill and McLean who used surface EMG on abdominal muscles during near max PFM contraction and found co contraction of abdominal muscles with transverse abdominus being most active (224.3% increase in TrA during PFM contraction).

They also reference a study by Thompson and O’Sullivan which showed that during PFM contraction, all abdominal muscles were more active

Sapsford et al: Study did not record abdominal muscle activity and did not include this statement.

  

No RCT were identified showing that a PFM contraction increases TrA strength and function

2) Is there evidence to support the hypothesis that there is a co-contraction of PFM during TrA contraction? Opposite of question one

According to a study by Bo, the PFM contracts during a contraction of the TrA.  They did find 30% of participants had downward movement of levator plate during TrA contraction (incorrect contraction).   However, Levator Ani movement upward (correct contraction) was 61.6% greater with PFM contraction alone versus TrA alone. In other words, if you want  a PFM contraction, it is best to directly contract the PFM rather than training the TrA and hoping the PFM comes along.

Sapsford et al: Failed to make concurrent measurement of abdominal muscle activity and can’t confirm strategy used.

  

3. ) How effective is TrA training in treating UI?

No RCT to date on TrA training alone on UI

Sapsford et al:  Authors of retort do not support the notion that training the TrA alone is a viable treatment for UI

Doumoulin compared adding TrA to PFMT

• Weekly training with PT and HEP for 8 wks, 62 women, with SUI

• Cure rates

o 70% PFMT ( n=20)

o 74% PFMT and TrA ( n=23)

o 0% control (back massage) ( n=19)

• No additional effect to add TrA training to PFM training in control group.

Sapsford et al: The author’s interpretation of Hung study reinforces this paper’s misinterpretation that TrA can be a stand alone treatment. Including TrA is part of a comprehensive program aimed at coordination of activity of muscles around the abdominal cavity.

4) How effective is PFMT in Rx of UI?

This is well proven and has strong evidence according to many RCTs and systematic reviews. Good list of references given. PFMT is better than no treatment for SUI, UUI and Mixed.

Author’s opinion is that PFMT on overactive bladder sx are not convincing. Better for SUI ( cure rates between 44 and 70%)

PFMT increases PFM strength has potential to increase muscle volume and lift levator plate. Positive assoc between MVC and improvement in leakage has been shown

Sapsford et al: Study cited trained abdominal muscles , trunk extensors and PFM. Impossible to determine if training effect is due to PFM contraction in isolation or due to coordination of muscles surrounding abdominal cavity.)

Conclusion:

Evidence shows TrA contraction occurs during PFM contraction but PFM contraction may not occur with TRA contraction in clients with PF dysfunction.

High evidence to show PFMT helps pts with UI and the “knack” should be learned before increased IAP. Need for RCT exists for evaluation effectiveness of TrA training for UI

  

Sapsford et al: Authors state abdominal muscle contraction may increase IAP. True. Authors failed to state that PFM has been demonstrated to increase IAP.

 Sapsford and Hodges agree with basic premise of Bo’s report that caution should be exercised when introducing modifications to existing interventions, but are concerned that this paper contains many inaccuracies giving a biased view. Say they oversimplified the issue of the complexity of coordination between abdominal and PFM activation. Junjinger et al show that PF displacement, PFM activity and IAP are dependent on the coordination of the abdominal muscles. Abdominal muscle activity has positive effect (co-contraction of PF) and negative effect (descent of floor from IAP) and treatment planning must be carefully planned to optimize this. It is an oversimplification of the issue to ask if pts with PFM dysfunction should learn to isolate TrA as a stand alone treatment for PFM dysfunction.  Perhaps the authors were attempting to demonstrate that PTs must directly train the PFM 's rather than to indirectly train them through the TrA training.

Say jury is still out about the value of abdominal muscle control in management of PFM dysfunction, but there is sufficient data to suggest it is a worthy avenue in clinical trials.

 Discussion of the group was regarding the importance of learning to correctly contract TrA to avoid increase in IAP and decent of PFM. This can be a factor to consider with POP rehab. A major part of therapy for POP should focus on strategies used with functional activities and preventing valsalva.

Jane O’Brien, PT, MSPT

Pelvic PT Distance Journal Club May 4, 2011.