Physical and occupational therapy outcomes: Adolescents’ change in functional abilities using objective measures and self-report

1.1 Background

Pediatric chronic pain is on the rise, affecting up to 40% of adolescents, causing significant functional impairments (5–10%) [1, 2, 3, 4]. Adolescents with chronic pain often struggle with every day activities, family interactions, participation in sports or leisure activities, and consistent school attendance. As a result, many begin to experience worsened self-perceived health status [5, 6], including their perception and ability to complete physical tasks.

An interdisciplinary rehabilitation approach is a useful model of care for adolescents severely affected by chronic pain and functional disability [5, 7, 8, 9, 10]. Given the nature of chronic pain, dramatic reduction in pain is not anticipated or targeted as an early outcome to intervention. Rather, treatment aims to increase independent symptom management and improved daily functioning [2, 11]. Research supports education and participation in physical activity/exercise can reduce pain and limit disability [12]; therefore daily physical, occupational, and recreational therapies are a necessary part of rehabilitation. Therapy goals for adolescents with chronic pain are to improve independent, consistent daily physical functioning, and to reduce sedentary habits and activity avoidance.

Due to a global sense of impairment and lack of insight, many adolescents who experience chronic pain often perceive that they are limited in daily functional tasks and basic physical activity [7, 13]. For this reason, gains in therapy physical functioning should be measured with both self-report and objective measures. Selfreport tools help track perceived functional gains and demonstrate the psychological aspects of independent functioning. Objective measures can enhance assessment of functional gains by isolating the psychological aspects of perceived confidence.

There is limited research supporting specific outcome measures for adolescents with chronic pain in rehabilitation, specifically targeting physical or occupational therapy interventions. Commonly used therapeutic objective measures and assessments include the BOT [14], GMFM [15], and TUG [16]. Although helpful, these standardized tests can be time consuming, require additional resources, and be limited by areas of functioning or age ranges. Other standardized physical measures exist for high level athletes (PACER test, shuttle run, etc. [17]), but are less ideal in deconditioned adolescents. Few easily administered and appropriate objective measures exist for evaluating and tracking physical function for adolescents with chronic pain.

There exists a need for easily administered self-report and objective measures to examine adolescent functioning and change in functioning following chronic pain rehabilitation. Past research suggests the utility of self-report measures, but the utility of objective measures and their relation to self-report measures remain unknown.

1.2 Hypothesis

This study examines the use of two self-report measures and 5 objective fitness exercises to track physically oriented functional gains within a pediatric chronic pain rehabilitation program. Hypotheses include:

1. Adolescents completing a multidisciplinary pain rehabilitation program, which targets physical functioning, will report perceived functional gains from admission to discharge.

2. Adolescents will similarly demonstrate improvements in objective measures as they do in their rating of perceived functional gains.

3. Self-report and objective measures will correlate at both admission and discharge.

4. While we do not expect a large decrease in pain during rehabilitation, we anticipate that adolescents who report or demonstrate gains in physical ability will also demonstrate a mild reduction in reported pain intensity.

2.1 Participants

116 Children and adolescents (hereafter referred to as adolescents) ranging in age from 8–19 years old, with varying chronic pain diagnoses, were treated in this chronic pain rehabilitation program. Data for this study was collected retrospectively on all program participants. The most common diagnoses include headaches and migraines, back pain, abdominal pain, amplified musculoskeletal pain syndrome (AMPS) and complex regional pain syndrome (CRPS) (Fig. 1). Adolescents were excluded from data analysis if they: opted out of specific treatment, left the program early, withdrew consent, incomplete data forms, or participation in the program was extended past the typical 3–4 weeks (38 adolescents). Data of both self-report and objective measures for 78 adolescents was reported.

Fig. 1

Percentage of cases by diagnosis.

2.2 Program/procedure

Chronic pain rehabilitation on a multidisciplinary level focuses on improved strength and endurance, facilitating return to daily life activities, and using appropriate self-directed coping and pain management skills [5, 6, 7]. Participants were typically seen for three weeks including both inpatient and day hospital care for full days. Within the program, adolescents participated in rehabilitation therapies, psychological services, medical subspecialty care, alternative therapies, and school services. Since an adolescent is part of a family unit, parents were also involved in education and observations with providers to help them support continued progress once home [6].

The goal of chronic pain rehabilitation has evolved from eliminating pain to managing pain so that overall functioning is improved. Progress is measured in part by physical functioning despite continuation of pain and symptoms [7].

2.3 Physical and occupational therapy treatment

Physical and occupational therapies were completed in both group and individual sessions for 3–4 h daily in land and pool settings. In therapy sessions, adolescents worked on isolated strengthening of appropriate musculature, endurance, proprioceptive and sensory training techniques, and other exercises or skills to help each adolescent return to highest level of function necessary. All adolescents spent time working on individual goal-oriented activities and independence with strengthening and endurance tasks while focusing on improved body mechanics and posture during exercises [6]. Limited time was spent on passive therapeutic interventions (e.g., massage, micro current, TENS), as the goal of therapies is to promote independence [18]. Parents were included for weekly education on therapeutic activities, barriers to improved function, appropriate modifications and accommodations, and expectations for going home [6]. At times, this included parents being more hands-on, working on behavioral planning, and observing an increased number of sessions. At a clinical level, improvements were measured by meeting specific therapy goals relating to improvements with presenting impairments, functional limitations or restrictions [19] (e.g., walking 100 yards without a walker/cane or tolerating a daily stretching and exercise regimen without pain complaints).

2.4 Measures

The reported data was collected upon the day of admission and at the day of discharge and retrospectively reviewed. Data collection through REDCap has been approved by the Institutional Review Board and is on the clinical database registry [20].

2.5 Lower Extremity Functioning Scale (LEFS) and Upper Extremity Functioning Index (UEFI)

Self-report tools have been useful to track perceived functional gains and demonstrate the psychological aspects of independent functioning. The Lower Extremity Functional Scale (LEFS) [21] and the Upper Extremity Functional Index (UEFI) [22] are self-report measures that were developed because of the need for a simple outcome tool that could be used to track an individual’s function level throughout the course of rehabilitation. Additional benefits to these measures that may not be realistic for other functional outcome measures include ease of administration, application to any musculoskeletal disorder, and generalizability to settings outside of the clinic or hospital. Both measures can be easily incorporated into individual or group treatment sessions, and are completed by the adolescent with guidance from a physical or occupational therapist [6]. Past research using these measures has demonstrated their utility as an outcome measure in pediatric pain rehabilitation [6].

The LEFS and UEFI are 20-item self-report measure about one’s perceived ability to perform everyday tasks with lower extremities and upper extremities, respectively. Individuals rated each item on a 0–4 likert scale (0 = extreme difficulty or cannot perform and 4 = no difficulty). Scores were summed for a possible score of 0–80. The LEFS has demonstrated good internal consistency (Cronbach’s alpha = .96) as well as test-retest reliability (r = .86). The UEFI has demonstrated good internal consistency (Cronbach’s alpha = .94) as well as test-retest reliability (r = .95). Both scales are also sensitive to change in functioning—a minimum detectable change score of 9 points is considered clinically important [6, 19, 23].

2.6 Objective measures

Simplistic objective measures, such as activities used in nationally recognized fitness tests for school aged children (i.e., fitness gram test [24]), may effectively provide information on improvements in function. Therapists in this program have used consistent objective measures of function as part of clinical care. Some measures are used with typical developing peers within the school setting [18, 23, 25, 26, 27, 28].

The objective measures used in programming for data collection included: push-ups, crunches, prone extension, step ups, and jump rope (number of repetitions during 60 s). The therapist kept track of time and provided prompting to improve alignment and body mechanics while the patient self-counted repetitions and logged them, as would be done in a school setting [24]. The ability for participants to self-count and track information is important as taking a more independent role in their progress can help promote long term gains [29]. Adolescents completed these activities in group setting and tracked these measures weekly throughout the program allowing for visualization of progress. The amount of repetitions for each exercise was recoded into an ordinal variable: zero, 1–5,6–10,11–20,21–30,31–40,41 + reps. Admission and discharge data were recorded for this study.

2.7 Pain

A single-item measure evaluated pain severity rating in last 24 h using a numerical rating scale (NRS) from 0 (no pain) to 10 (worst pain) [19].

2.8 Analysis plan

This data was captured in a REDCap database [20], then converted to an SPSS 22.0 dataset for analyses. Paired t-tests evaluated change in self-report measures (LEFS, UEFI and pain) over time. Wilcoxon signed ranks tests evaluated change in objective performance on standard measures over time. Spearman correlation coefficients were calculated to evaluate the relationship between self-report ratings of functioning and objective performance measures at admission and discharge. In order to demonstrate the association between change in physical functioning and change in self-reported pain, a series of regression analyses were performed. First, baseline measures of LEFS, UEFI, objective measures and pain were entered to predict these same measures at discharge. Standardized residuals were retained to represent change scores. Next, residualized changes scores for LEFS, UEFI, and objective measures were entered to predict residualized change in pain in seven separate models.

3.1 Participants

Out of the 116 adolescents enrolled in the study, 78 met inclusion criteria. There was no significant difference between patients included versus excluded in analysis on any demographic, diagnosis, or other major study variable. The average age was 15.1 years (SD = 1.83) and the majority (77%) were female, consistent with other research on this population. Adolescents had various diagnoses including headaches and migraines (29.1%), abdominal pain (10.4%), AMPS (11.4%) and CPRS (26%) as seen in Fig. 1. Other diagnoses included back pain, fibromyalgia, reflex neurovascular dystrophy, postural orthostatic tachycardia syndrome, foot pain, and Ehlers–Danlos syndrome. Most participants also presented with at least one other secondary pain diagnoses. The chronicity of pain was recorded as less than 6 months (13.5%), 6–12 months (18.8%), 12–18 months (10.4%), 18–24 months (13.5%), and almost half (43.8%) of the participants experienced chronic pain for more than 24 months.

3.2 Self-report data

Self-report data is presented in Table 1. Participants reported a statistically significant increase in lower extremity functioning (t = −9.080, p − 0.001) throughout rehabilitation. They also reported statistically significant increase in upper extremity functioning (t = −8.439, p < 0.001). Using criteria reported by scale developers, clinically significant increase in lower and upper extremities were identified in 70.5% and 55.1% of participants, respectively. Participants also reported a mild reduction in pain from 6.7 to 5.5 during rehabilitation (t = 2.879, p = 0.006). Secondary analysis evaluated whether functional improvements differed across clinical diagnosis; there were no significant differences in self-reports between diagnosis groups.

3.3 Objective data

Using objective measures of functioning revealed similar results. In Fig. 2 repetitions of standard exercises from admission and discharge data was reported. The median scores at admission were, respectively: push-ups (11–20), crunches (21–30), prone extensions (31–40), step ups (21–30), and jump rope (41+). The median scores at discharge were, respectively: push-ups (31–40), crunches (41+) prone extensions (41+), step ups (31–40), and jump rope (41+). All scores were significantly improved across the three weeks of rehabilitation (Table 1). Wilcoxon signed ranks tests demonstrated significant change in all measures (p <0.001, with the exception of prone extensions with p = 0.008).

Fig. 2

Performance on objective measures of physical functioning for participants in pediatric chronic pain rehabilitation, at admission and discharge.

3.4 Association between self-report and objective measures

Spearman correlations are listed on Table 2. Self-report measures (LEFS and UEFI) were significantly associated with most objective measures of functioning at baseline (sig. r’s ranged from .256 to .631). Correlations were slightly weaker at the discharge from the program (sig. r’s ranged from .224 to .399) with more nonsignificant associations. At both time points, self-report measures of functioning held stronger associations with self-report of pain, though again these associations were weaker at discharge.

3.5 Association between functioning and pain

Change in self-report measures of functioning did not significantly predict change in pain ratings during the 3-week rehabilitation program (Table 3). Change in self-reported functioning accounting for only approximately 3% of the variance in change in pain in both LEFS and UEFI (both F statistics nonsignificant). When evaluating objective measures, only change in jump ropes predicted change in pain. An increase in one’s ability to jump rope predicted a reduction in pain over the three weeks (F = 6.412, p < 0.05). All other measures were non-significant, accounting for less than 1% of change in pain scores.

4.1 Self-report

Data supported the hypothesis, and current efforts in rehabilitation [30], that adolescents would demonstrate statistically significant gains in both upper and lower extremity functioning following the program. More than half also report clinically significant gains in functioning over the 3 weeks of rehabilitation. Frequent practice of individualized functional tasks (i.e., simulation of school mobility, completion of house hold chores, and practice of leisure and recreation) during the program may lead to increased perception of physical functioning. This material can help demonstrate how self-report reflects ones sense of confidence and the importance of perceived outcomes on improving quality of life [7, 13, 30, 31, 32].

4.2 Objective measures

Patients also objectively demonstrated significant gains in functioning. Most patients demonstrated significant improvements in all 5 exercises from admission to discharge, completing higher repetitions at the end of the rehabilitation process as captured in Fig. 2. Not only can exercise intervals be used to track objective gains but are inherent to a rehabilitation process. Strength training is an important component to the rehabilitation process to promote functional gains in patients with chronic pain [33]. It was highlighted by therapists that the adolescents should focus on alignment, breathing, efficient and coordinated use of muscle groups, and quality of movement instead of the specific quantity of repetitions. To this end, participants at times made less significant increases in repetitions counted due to improvements in overall body mechanics.

4.3 Correlation between all measures

Both self-report measures and objective measures are helpful outcomes for assessing physical functioning and in this specific study correlated at both admission and (to a lesser degree) discharge (Table 2). Objective data correlated at admission with self-report data and pain intensity. At discharge objective data partially correlated with self-report data, more specifically lower extremity measures compared to the upper extremity measures (Table 2).

Patients with higher self-reports of function completed a higher number of repetitions with objective tests, further validating the use of self-measurement as outcome variables. However, less significant correlations at discharge suggest these measures are distinct constructs, each adding unique value to understand patient and his/her response to rehabilitation. Self-rated and objective tools each have their strengths and together may show a more global picture of physical functioning from admission to discharge. These correlations also support that when perception and confidence in one’s functional abilities was higher, the patient was able to participate at a higher level of activity. Higher correlations between UEFI/LEFS and pain perception, suggest both more closely address cognitive or perceptual aspects of patient disability than objective measures of function. Given the lower correlation with self-report pain at discharge, we would also conclude that those who understand the program philosophy (i.e., that functional gains must occur prior to potential decreases in pain), show increases in self-reported and objective functioning, even though they still report pain.

While our data did indicate a modest decrease in pain, this is not surprising. Clinically, we often notice changes in pain occurring after extended periods of increased functioning. While we anticipated changes in pain would be associated with improvements in functioning, the lack of this finding is not surprising, especially after only 3 weeks of rehabilitation.

4.4 Limitations

This study did have limitations that should be addressed, many of which point to areas for future research. First, neither selfreport nor objective measures had control groups consisting of adolescents without pain or adolescents with chronic pain not undergoing pain rehabilitation; future research could examine LEFS and UEFI as outcome measures using a group comparison model. Second, formal long-term changes in functioning were not assessed; while short term changes were captured, one cannot assume gains will be maintained at home. It will be important for future studies to assess functioning at a distant time point after rehabilitation to evaluate carryover effects of rehabilitation. Third, the objective measures originally used and collected for this study may not be the most suitable to accurately reflect change in functional strength and endurance. Further research and application of alternative functional strength and endurance exercises may be more helpful.