The current study assessed FMS proficiency in children with bronchiectasis and examined the relationship between FMS proficiency and habitual PA. The results show that children with bronchiectasis experience significant developmental delays in FMS proficiency. Just eight of the 46 children achieved their age equivalency for locomotor skills, while just four children achieved their age equivalency for object control skills. Fewer than 5% of the sample demonstrated mastery in the run, gallop, hop, and leap; while fewer than 10% demonstrated mastery for the two-handed strike, overarm throw, and underarm throw.
Table 3
Mean (95% Confidence Interval) of physical activity in children meeting their age equivalency and not meeting their age equivalency
PA Variable
|
Age Equivalency for FMS Proficiency
(Mean and 95% CI) a
|
Difference
(Mean and 95% CI)
|
P-Value
|
|
Meeting (N = 9)
|
Not Meeting (N = 32)
|
|
|
MVPA b
|
51.7
(45.9–57.5)
|
36.6
(24.2–49.1)
|
15.1
(0.3–29.8)
|
0.04
|
SED
|
357.9
(312.0–403.8)
|
356.9
(335.6–378.1)
|
-1.0
(-55.4–53.3)
|
0.96
|
L_ACT_G
|
301.2
(260.4–341.9)
|
287.2
(268.3–306.0)
|
14.0
(-62.3–34.2)
|
0.56
|
M_ACT_G
|
22.1
(18.1–26.2)
|
10.7
(2.0–19.5)
|
11.4
(1.1–21.7)
|
0.03
|
WALK
|
23.1
(14.3–32.0)
|
24.3
(20.2–28.4)
|
-1.2
(-9.3–11.7)
|
0.82
|
RUN
|
2.8
(0.2–5.4)
|
5.3
(4.1–6.5)
|
-2.5
(-0.6–5.6)
|
0.11
|
Abbreviations: MVPA = moderate-to-vigorous physical activity; SED = Sedentary activities; L_ACT_G = Light intensity activities and games; M_ACT_G = moderate-to-vigorous intensity activities and games. WALK = walking; RUN = Running
a. Means adjusted for gender and accelerometer wear time.
b. MVPA calculated by summing daily time in M_ACT_G, WALK, and RUN as classified by a Random Forest PA Classifier [18].
A major finding of the current study was that FMS proficiency emerged as a strong determinant of PA performance in children with bronchiectasis. Children achieving their age equivalency for either locomotor or object control skills exhibited significantly higher levels of daily MVPA than those with developmental delays in FMS. Notably, the differential in daily MVPA was attributable, in large part, to a 2-fold difference in daily participation in moderate-to-vigorous intensity activities and games. This was an important finding considering that participation in such activities would generally require a prerequisite level of FMS proficiency. Notably, there we no significant differences in sedentary time or PA classes less dependent on FMS proficiency (e.g., walking and running).
To date, only two previous studies have evaluated FMS proficiency in children with chronic respiratory conditions [21, 22]. In contrast with the results of the current study, both found no evidence of developmental delays in FMS. Gruber et al. [22] assessed motor performance in preschool-aged children with cystic fibrosis (CF) and found motor quotient scores, based on the average of seven motor tasks, to be within the normal range. Similarly, Bender et al. [21] observed no evidence of motor delays in a sample of 67 children with severe chronic asthma. The discrepancy in findings may be explained, in part, by differences in the operational definition and assessment of motor competence. Notably, both studies used assessment batteries that measured both fine and gross motor skills and evaluated skills more closely related to athletic ability (i.e., strength, speed, agility) than FMS proficiency.
The results, however, are consistent with previous investigations evaluating FMS proficiency in other pediatric patient groups such as cancer survivors and children with congenital heart disease. Hartmann et al. [23] evaluated movement competency in 120 pediatric cancer survivors. Twelve months post treatment, two-thirds of children scored below the 50th percentile on the movement ABC. Neuman et al. [24] compared the FMS proficiency of pediatric cancer survivors with a reference group of 300 healthy children. Cancer survivors were significantly less likely to exhibit mastery on seven key FMS (sprint run, vertical jump, side gallop, leap, catch, kick, overarm throw) than healthy children. Box and colleagues [25] evaluated the motor performance of 18 children with congenital heart disease. Compared to healthy controls, gross motor performance was significantly delayed. Finally, Holm et al. [26] observed that nearly half of children with complex heart disease had significant motor delays. Of note, none of these studies concurrently measured PA or examined if differences in PA are explained by delays in FMS. Collectively, these findings suggest that children with chronic health conditions are at increased risk for developmental delays in motor proficiency, suggesting that clinicians may need to assess movement competency as part of routine practice; and when indicated, refer patients to developmentally appropriate therapeutic exercise programs to increase movement competency.
The observed age delays in FMS proficiency in children with bronchiectasis may be attributable to a number of factors. FMS are not naturally acquired but need to be taught and practiced (31). Therefore, it is possible that periods of inactivity, precipitated by exacerbations and/or the time constraints imposed by frequent medical appointments and therapy sessions may limit opportunities to practice and refine movement skills. Lack of parental support for PA may be another reason, as overprotective parents may discourage participation in sport and PA programs believing that exercise will provoke coughing and cause physical discomfort [7]. Finally, a lack of core strength and balance may contribute to poor FMS proficiency, as both are necessary for achieving mastery on most of the FMS assessed by the TGMD-2 [8].
The current study has several strengths. To our knowledge, it is the first study to systemically evaluate the relationship between FMS proficiency and PA in children with bronchiectasis. FMS proficiency was measured using the TGMD-2, a widely-used and validated process-oriented assessment tool with published norms for both object control and locomotor movement skills. In addition, PA was measured objectively using a wearable sensor and the PA outcomes were derived using state-of-the-art machine learning data processing methods [27]. The application machine learning methods allows researchers to monitor not only the intensity of physical activity, but also the quality of movement behaviors. In contrast to traditional cut-point methods, which simply estimate time spent in moderate-to-vigorous PA, the random forest classifier deployed in the current study allowed monitoring of active game play and sports as component of overall participation in MVPA. This was key given that participation in active games and sports requires greater FMS proficiency than walking and running.
Opposing these strengths were a number of limitations. First, the cross-sectional study design means it is not possible to infer causal relationships between FMS proficiency and PA participation. Second, the random forest PA classification algorithm used to measure daily MVPA was trained on laboratory-based activity trials which may not fully replicate PA performance under true free living conditions [28]. Third, participants were recruited from a single public hospital in Brisbane, Australia and cannot be considered representative of all children with bronchiectasis. In addition, because children with less than 3 valid monitoring days were excluded from the analysis, we cannot rule out the possibility of selection bias (i.e., physically active children more likely to be included in the analytic sample than low-active children). However, given the small number excluded, and the generally low levels of FMS proficiency and PA levels in our sample, this is unlikely. Future studies should evaluate the relationship between FMS proficiency and PA levels in larger, more representative samples of children with bronchiectasis. Samples should be sufficiently large and diverse to determine if the relationship between FMS proficiency and PA is moderated by demographic, socioeconomic status, and health characteristics.