Tests & Measures: A Resource for Pediatric Physical Therapy Practitioners

Functional Reach Test Article Summary

Article: Reliability and comparison of trunk and pelvis angles, arm distance and center of pressure in the seated functional reach test with and without foot support in children

Background: In order to maintain one’s balance during dynamic activities, and individual’s center of mass must stay within their base of support. The alignment of the trunk and pelvis are vital for maintaining appropriate sitting balance during activity. A commonly used measure of dynamic sitting balance is the ability to reach beyond an arm’s length, which can be measure utilizing the modified Functional Reach Test (FRT.) The modified FRT is typically performed in standing however, has increasingly been used while the subjects have been seated to measure the maximum amount of reaching in the anterior and lateral direction without falling. The seated modified FRT has been largely studied with foot support and with heavy emphasis on postural movements. The test-retest reliability of this exam in children has not been widely researched, however it’s understood that dynamic sitting balance is an important tool that can be used for screening and evaluating children. Therefore in order to be able to use the modified FRT in sitting for assessment of children, the test-retest reliability of maximum distance, movement strategies and other key factors needs to be established for typically developing children.

Purpose: The purpose of this study was to determine two things. The first being to determine an appropriate test-retest reliability when examining typically developing children’s trunk and pelvis joint angles, arm distance and the center of pressure (COP) excursion during the seated functional reach test (FRT). To address both purposes, two hypotheses were formed, one to address each of the research questions. The first proposed hypothesis was that there would be “no significant differences and excellent test-retest reliability in trunk and pelvis angles, distance of arm movement and COP at maximal reach in four directions during the seated FRT for two different test periods.”¹ To address the second purpose of the research, the following hypothesis was proposed that there would be “significant differences in trunk and pelvis angles, distance of arm movement, and COP excursion at maximum reach in four directions during the seated FRT with and without foot support.” ¹

Study Population: Fifteen typically developing children, eight of whom were female and seven were male, aged 9.30 4.10 years were utilized for this study. All participants were right arm dominant, had an average height of 136.30  22.70 cm, average weight of 34.97 17.16 kg, average trunk length of 29.93 6.44 cm, and an average arm length of 44.36 7.87 cm. Exclusion criteria included an recent history of musculoskeletal, neuromuscular or balance problems.

Methods: Subjects completed testing over the course of two separate visits, with one week between test dates. All data collection was performed by one researcher. During set up of the seated FRT, all subjects were weighed, measured for height (including arm length), and hand dominance was recorded. Prior to performing the seated FRT, all subjects had 16 retro-reflective motion markers placed with adhesive tape in the following areas: “1. Third metacarpal phalangeal joints; 2. ulnar and radial styloid processes; 3. olecranon processes; 4. acromioclavicular (AC) joints, 5. cervical (C7) spinous process; 6. sternal notch; 7. anterior superior iliac spines (ASIS); 8. posterior superior iliac spines (PSIS.)” ¹ For testing, all subjects were seated on an “adjustable wooden bench with a solid base fitted and placed on one force plate.” ¹ The adjustable nature of the bench allowed for the height to be altered allow for its use during trials without the subject’s feet on the floor. Subjects were instructed to sit with hips and knee flexed to 90 degrees, with 2/3rds of their posterior thighs supported by the bench, with ankles in a neutral position. This posture was utilized with and without foot support.

Each subject completed two reaching trial per arm, per direction (anterior, 45 ̊ anterior/lateral, lateral and 45 ̊ posterior/lateral), and were allowed one practice trial prior to formal data collection. The protocol for reaching was as follows: the subject was asked to reach as far as possible toward a target without falling that was adjusted to shoulder height of the subject. The target, which was a toy set up on a tripod, was then moved 2.5 cm further away from the subject’s hand. All trials began with the subject’s arm by their side. Data was collected via a three-dimensional Motion Analysis system, using six infrared cameras to capture the kinematic data.

Outcome Measures:

Modified Functional Reach Test (FRT):

·        Performed in sitting with foot support

·        Utilized as a measure of dynamic sitting balance in terms of the individual’s ability to reach beyond arm’s length.

·        Characterized by the “maximum distance reached by the arm at 90 ̊ of flexion in the forward direction without loss of balance”¹

·        For this particular study, the modified FRT was performed in four directions: anterior, 45 ̊ anterior/lateral, lateral and 45 ̊ posterior/lateral

·        The Modified FRT was performed with and without foot support.

Intervention: There was no intervention in this study.

Results: There was no significance between right and left upper extremity maximum reaching differences for any direction with and without foot support, therefore the following information is presented based on the right arm. There was significant correlation (p<0.01) between right maximum arm distance reached (with and without foot support and in all directions) for age, weight, height, trunk and arm lengths. Additionally, the data collected indicated that there was a significant difference (p<0.05) for reaching with foot support in all directions in comparison to no foot support. Looking at individual movements, it was evident that there was a significantly greater trunk flexion for anterior/lateral reaching with feet supported, significantly greater anterior pelvic tilt with lateral reaching (with foot support) and significantly greater trunk rotation to the right with posterior/lateral reaching without foot support.  There was no significance (p<0.05) for the following: the maximum arm reach distances with and without foot support, the trunk and pelvis joint angles with and without foot support, and COP excursion with and without foot support.

Overall there was excellent reliability for maximal reach distance in all four directions with and without foot support, which aligned appropriately with clinical measurements for adults when using the seated FRT. Furthermore there is excellent to fair reliability in terms of trunk and pelvic joint angles and COP excursion.

Strengths: The information acquired on the two additional directions to assess dynamic sitting balance is a strength of this article. This new research can make this test useful for a greater number of individuals and improves the ability of the test to be used as a tool to assess directional activities used on a daily basis.

Limitations: This study saw a few specific limitations that affected the outcomes measured. The first was the sample size. With a sample size of fifteen, it is hard to create evidence that suggests how reliable and valid the test is within a larger sampling of individuals and if the evidence that indicates the two new directions of reaching are appropriate to measure additional reaching capabilities. The second limitation is the attention span and ability of children to perform consistently and at their optimal functional level during testing.

Conclusion: Overall, this research indicates that there is excellent reliability in all four directions utilized in the seated FRT for maximum arm distance reached. This is true when performed with and without foot support. When comparing the seated FRT with and without foot support, there is evidence that indicates the ability to reach further in all directions is significantly greater with foot support. That being said, there is however, no significant difference in the trunk and pelvis angles and COP movement with and without foot support. As a result of this study and the data collected, there is a strong indication that including reaching in the anterior/lateral and posterior/lateral directions during the seated FRT is beneficial for providing information on reaching abilities in children, however the removal of foot support during seated FRT is not considered beneficial.

Reference:

1.      Radtka S, Zayac J, Goldberg K, Long M, Ixanov R. Reliability and comparison of trunk and pelvis angles, arm distance and center of pressure in the seated functional reach test with and without foot support in children. Gait & Posture. 2017;53:86-91. doi:10.1016/j.gaitpost.2016.12.026.