Monday, August 19, 2013

Trunk strength and mobility changes in children with slowtransit constipation.Chase JW, Stillman BC, Gibb SM, Clarke MC, Robertson VJ, Catto-Smith AG, Hutson JM, Southwell BR. J Gastroenterol Hepatol. 2009 Dec;24(12):1876-84.

Laura Scheufele PT, DPT, WCS
August 7, 2013

Primary Aim: To determine whether children and adolescents with STC have different trunk musculoskeletal characteristics that might be related to their defecation difficulties, compared to controls. Additional aims were to determine the usual activity patterns of slow transit constipation (STC) children.

Subjects: 41 children who met the STC criteria, aged between 7-18 years, were matched for age and sex in the control group. Criteria for selection into the STC group included diagnosis by radionuclear transit studies, and at least 2-year history of medical management. The control subjects recruited by requests for volunteers fromAustralian Scouting groups, and children of colleagues. The parents of each of the control subjects were interviewed and confirmed no known relevant musculoskeletal disorders or constipation history requiring medical management. 

Exclusion criteria: Hirschsprung disease, celiac disease and endocrine abnormalities.

Study Design: Descriptive with age and gender matched controls


Outcome measures:

Tripod mounted camera used to capture photographs that were transferred to a computer, and then used to measure the linear distances and joint angles required for analysis. A ruler of known length was included in all photographs to allow calibration of the linear measurements in centimeters.

To determine Marfanoid characteristics:

1)    A posterior view photograph taken with subject standing in bare feet with upper limbs outstretched sideways to form a “T”. (Marfanoid sign is upper limb span-to-height ratio > 1.03.

2)    Subjects asked to encircle each wrist with the thumb and middle finger of opposite hand. Noted whether the thumb and finger did not meet, touched, or overlapped. Over-lapping (signifying long fingers) is a positive Marfanoid sign.

Trunk mobility angle: The sum of the obtained ranges of passive trunk flexion and extension. End ranges calculated as follows: Combined passive thoracolumbar and hip extension:(Figure 1a) Angle measured as the long axis of the thigh and a second axis forming a tangent of upper thoracic spine while in prone press up with pelvis maintaining contact.

Passive combined thoracolumbar and hip flexion: (Figure 1b) Axis as above with patient positioned in standing with knees extended while attempting to place the hands flat on the floor.

Angle of pelvic tilt and thoracolumbar flexion in sitting (on stool that is 42 cm to simulate standard toilet height) with one upper limb supported forward. Sagittal plane sitting posture assessed from lateral photo to assess pelvic tilt angle and thoracolumbar flexion-extension.

Active trunk extension: In prone position with arms outstretched over the head, subjects asked to lift (arch) the back as high as possible while assistant was stabilizing the legs. The angle of trunk extension measured as with trunk mobility. 

Abdominal anteroposterior diameter at rest, with bulging and with retraction: Measured in centimeters through a transverse plane at the junction of the lower one-third (defined from level of greater trochanter to mid-abdominal plane) and upper two-thirds of the trunk (from mid-abdominal plane to suprasternal notch). This distance was also calculated as a percentage of the relaxed anteroposterior abdominal diameter to standardize for variations in trunk girth between the subjects.

Activity level: Average hours per week of physical activity (walking, cycling, bike-riding and sports) and sedentary activity (television time, computer activities) outside of school time. Categorized sedentary time as low (<15h high="" or="" week="">15 h/week).


Subject characteristics: No differences between groups noted in regards to age, gender, BMI, bodyweight as percentile, wrist encircling overlap, or upper limb/height ratio > 1.03 %

Trunk mobility: No significantdifference betweenSTC group and control group when analyzed as the sum of the flexion and extension, or individually. All female subjects had a significantly greater total range of flexion-extension and passive trunk extension compared to the males.

Angle of pelvic tilt and thoracolumbar flexion in sitting: (Table 2) Significantly more “positive pelvic tilting” (less posterior pelvic tilt) and less flexed thoracolumbar spine angles in the control subjects in relaxed, bulging, and retracted positions.

Sitting posture also assessed with both arms at side to determine of the forward supported position changed the subject’s natural sitting posture. No significant different in pelvic tilt but small significant difference in thoracolumbar flexion.

Active trunk extension: Maximal range in the STC subjects was significantly less than the controls. (23.4 +/- 10.3 degrees vs. 29.3 +/- 11.2 degrees.

Abdominal diameter: The anteroposterior diameter significantly greater in the STC subjects in relaxed, bulge and retracted position. Relative to the resting diameter the STC subjects bulged by an average 2.8 +/- 4.6% vs. 5.1 +/- 5.0% of the controls which was a statistically significant difference; but not significantly different with respect to the retraction.

Activity level: A significantly different interaction between physical and sedentary hours in the STC and control groups noted. The STC group found to relationship of activity such that those who participated in relatively high levels of activity typically had low sedentary activity hours and vice versa. In contrast the control group, subjects with high sedentary hours had high physical activity hours, and those with low sedentary hours had low physical activity hours. 

Discussion: This is a landmark study to assess trunk musculoskeletal characteristics in children with STC. In the STC children there was reduced abdominal bulge ability observed but no difference in respect to retraction ability. The STC group also noted to have increased AP abdominal diameter and generally more flexed posturing.  Speculation as to this difference in AP diameter ranged from potentially a more full colon could impact the diameter to greater size of the children (although no significant difference in BMI or weight percentiles.  The investigators did not assess the subjects’ typical defecation strategy, which may have provided additional insight into the neuromuscular pattern, i.e. if the STC population is retracting rather than bulging with defecation, this could give additional insight into the differences.

Strengths: Age and gender matched controls. Calibrated measurements.

Weaknesses: No specific landmark used for AP measurement of bulging, rest and retracted, other than “ mid-abdominal plane”. Measurement of activity profile did not account for the full day. Hamstrings may have also influenced passive flexion measurement. No measurement of typical defecation strategy.

Conclusion: The STC subjects were found to have less ability to voluntarily bulge the abdomen and were less able to actively extend the trunk. The STC children also noted to have a more flexed defecation sitting posture. In contrast no difference in actual spinal mobility was noted between the 2 groups. Lastly there was a difference in the relationship of physical and sedentary activities, with the STC group having a reciprocal pattern.

Impact on practice: The authors suggest clinicians place a greater focus on awareness and training of the trunk muscles and correction of sitting posture in the management of children with STC. Now that these characteristics have been identified, further research is required determining if specific treatment targeted at these differences are successful at changing the STC. In addition, the adult population needs to be evaluated.

Questions for discussion
1)    What has been the clinician’s experience with the STC population? Success rated compared to defecatory dysfunction?
2)    Has there been observation of a “typical” STC posture?
3)    Would the clinicians have chosen different methodology for any of the objective measures?
4)    What is the next step for researchers?

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