The goal of this study was to examine the clinical value of information about motor performance in daily life in stroke patients for counseling and rehabilitation planning purposes. To do so, we focus on individual patients and discuss how information about motor performance can be used as a decision aid for the planning of individual rehabilitation programs or for counseling. The functional status of the 15 included patients was heterogeneous (Table 2), with NIHSS scores ranging from 0–10. The capacity measures of walking (walking speed between 0.5 and 1.9 m/s on the 10 MWT) and upper-limb functioning (ARAT scores between 0 and 57) also varied substantially among patients. We considered this heterogeneity in the patient population to be representative of a rehabilitation setting.
Physical activity and walking
In line with previous research [31,32,33], the patients showed little physical activity on average, with a low fraction (12%) of time spent walking, and most of the time (69%) spent performing sedentary behaviors, i.e., lying or sitting (Table 2). The times spent walking and performing sedentary behaviors were highly variable among patients, irrespective of walking capacity (Fig. 2). The following patient examples demonstrate substantial discrepancies between the walking capacity and physical activity level in some patients. Patients #1, 4, 12, and 14 were rather active and spent 17–20% of their time walking. However, among these patients, only #12 was a comparably (i.e., compared to the other patients in this report) good walker according to the capacity tests (TUG: 10 s, 10 MWT: 1.7 m/s), whereas patients #4 and 14 were among the slowest walkers according to the capacity tests. On the other extreme were patients #5—9, who spent little time walking (5–8% of time) and were mostly sedentary (68–88% of time). Among these were patients with low as well as high walking capacities; patient #9 had a low walking capacity (TUG: 27 s, 10 MWT: 0.7 m/s), whereas patient #8 had a high walking capacity (TUG 10 s, 10 MWT 1.7 m/s).
Because a sedentary lifestyle is prevalent after stroke and constitutes an important vascular risk factor, counseling to increase daily physical activity is generally recommended for all stroke patients . However, advocating a more elaborate program, such as a behavioral lifestyle interventions  to increase physical activity, may not be appropriate in patients who are active and meet the current recommendations, such as patients #1, 4, 12, and 14 (who spent 17–20% of their time walking). Information that a patient is mostly sedentary and spends little time walking may prompt the rehabilitation physician to enquire about the reasons, which may include low cardiorespiratory fitness, fear of falls, fatigue or depression [36, 37]. Based on the findings, he/she may specifically address the relevant issues, e.g., by developing a treatment plan focusing on cardiorespiratory fitness, reducing the risk of fall, or treating fatigue or depression.
These examples show that knowing a patient’s physical activity profile could aid the rehabilitation physician in choosing appropriate rehabilitative therapies. Additionally, not prescribing an unnecessary therapy, such as a behavioral lifestyle intervention , to increase physical activity in a patient who already meets the recommendations may be more economical than prescribing the same intervention to all patients.
Another important aspect of walking performance in daily life is the length of each walking episode. When asked whether walking faster or walking farther was more important, 76% of stroke patients reported that walking farther was more important in daily life because it allowed access to community facilities . For older adults, a walking distance of 200–600 m was reported to be necessary for accomplishing community activities, such as going to grocery stores or banks . In line with other studies [3, 6], the lengths of walking episodes in daily life were low in our study, with an average of 29 steps per walking episode and an average maximal walking distance per walking episode of 410 steps. The lengths of walking episodes varied substantially among patients, irrespective of their walking capacity (Fig. 2). For example, patients #3 and #7 both had average walking capacities, but they were at the opposite extremes regarding their walking episodes. Patient #3 had an average of 62 steps/episode, and their longest walk was 1148 steps (the highest values in this study), while patient #7 had an average of 14 steps per episode, and their longest walk was only 62 steps (the lowest values in this study). The situation of patient #7, who had only short walking episodes despite good walking capacity, may not be an exception in stroke patients. Lord et al. found that up to one-third of home-dwelling stroke patients do not walk unsupervised in their communities even though they have achieved good clinical mobility outcomes . In patients with short average and maximal walking episodes (such as patient #7), an appropriate rehabilitation goal could be to increase the walking distance, with the intention of progressing from a household to a community walker and thus improving participation in daily activities.
On the other hand, some patients walked longer distances despite poor walking capacities. For example, patient #4 had one of the lowest walking capacities in this study (TUG: 32 s, 10 MWT: 0.53 m/s). However, in daily life, his walking performance was above average, with 32 steps per walking episode and a maximum walking episode of 492 steps. For this patient, longer walking episodes in daily life were not an issue, and increasing them would probably not be a priority. Instead, the rehabilitation goal could be to improve walking speed.
Counting daily steps with mobile devices has become a widespread practice in the general population. Numerous studies have explored the potential of counting daily steps to increase physical activity. A recent review and meta-analysis found that self-monitoring of step activity improved physical activity in patients with cardiovascular disease . In this study, we did not report daily step counts due to the short recording time. Instead, the step activity is normalized to the duration of the sensor recording and reported as the number of steps taken per recording hour. The hourly step activity varied substantially among the patients in our study, irrespective of walking capacity. For example, patient #5 had the lowest step count per hour despite an average walking capacity (TUG: 14 s, 10 MWT: 1.06 m/s). The rehabilitation physician could discuss this low-step activity with the patient, identify barriers, educate the patient about the effects of physical activity, and set a realistic goal of increased step activity .
Although walking performance was not related to walking capacity in some patients, as shown by the examples above and in other studies [6, 40], capacity and performance correlated moderately in studies with larger samples. For example, walking capacity, measured with the 6 min walking test, correlated with walking performance (steps/day) in chronic stroke patients [9, 43, 44]. However, the clinical capacity measures explained only up to 54% of the variance in walking performance in these studies, suggesting that daily life performance cannot be inferred from clinical capacity measures in individual patients. Based on these findings, one could be misled to expect better performance in a patient with higher capacity than in a patient with lower capacity (and vice versa) and would not expect substantial discrepancies between capacity and performance, as reported in some patients in our case series and in other studies. However, the fact that at least 46% of the variance in walking performance could not be explained by capacity measures in these studies agrees with the finding of substantial discrepancies between capacity and performance in some patients. The cases discussed above showed discrepant walking capacity and performance measures, and only a moderate correlation was observed between the two in other studies [9, 43, 44], indicating that clinical assessments alone do not allow a complete picture of a patient’s walking status.
Upper limb capacity
The clinical measures of arm capacity varied substantially among patients, ranging from severe to no clinical impairment (9 to 66 points on the FMA, average: 40.3 points, Table 3). As mentioned above, we considered this heterogeneity in the patient population to be representative of a rehabilitation setting. The total duration of impaired arm activity per hour of sitting ranged from 326 to 1570 s (≈ 5 to 26 min), with an average value of 866 s (≈ 14 min).
There were substantial discrepancies between clinical measures of arm capacity and sensor-derived measures of arm activity in some patients (Table 3). For example, among stroke patients with comparably good clinical capacity (FMA > 45 and ARAT > 40, i.e., patients #3, 6, 7, 8, 10, 11, 12, 13), there was a wide range in the absolute use of the impaired arm during sitting, ranging from 326 to 1570 s per hour of sitting time. Even patients #7, 8, 10, and 11, who all achieved the maximum score on the ARAT (i.e., 57 points), showed considerable variability in arm activity duration. For example, patient #10, who had 1346 s of normalized arm activity, had 4 times more arm activity than patient #7, who had 326 s. Patient reported arm use (MAL-14) in these four patients was above 4 points (= reportedly used the arm almost as much as they did before stroke), except in patient #10, with 2.6 points (= reportedly used the affected arm rarely or very rarely), who had the second longest arm activity of all patients. Discrepancies between capacity and performance measures of the upper limbs are well known [45,46,47] and can be explained by the concept of learned nonuse (i.e., failure to use the impaired arm despite adequate capacity) described by Taub and others [48, 49]. The recovery of capacity and performance in the upper limbs can diverge in some stroke patients, as shown in previous studies [5, 13], underscoring the need to assess both arm capacity and performance. Knowledge of low arm activity in daily life despite good arm function may prompt the rehabilitation physician to identify underlying reasons, such as learned nonuse of the affected arm. He/she may then plan specific interventions to increase arm usage in daily life, such as constraint-induced movement therapy .