Specific deficit analyses in motor performance and quality of life of pediatric cancer patients--a cross-sectional pilot study

Long-term Musculoskeletal Consequences of Chemotherapy in Pediatric Mice

Thanks to recent progress in cancer research, most children treated for cancer survive into adulthood. Nevertheless, the long-term consequences of anticancer agents are understudied, especially in the pediatric population. We and others have shown that routinely administered chemotherapeutics drive musculoskeletal alterations, which contribute to increased treatment-related toxicity and long-term morbidity. Yet, the nature and scope of these enduring musculoskeletal defects following anticancer treatments and whether they can potentially impact growth and quality of life in young individuals remain to be elucidated. Here, we aimed at investigating the persistent musculoskeletal consequences of chemotherapy in young (pediatric) mice. Four-week-old male mice were administered a combination of 5-FU, leucovorin, irinotecan (a.k.a., Folfiri) or the vehicle for up to 5 wk. At time of sacrifice, skeletal muscle, bones, and other tissues were collected, processed, and stored for further analyses. In another set of experiments, chemotherapy-treated mice were monitored for up to 4 wk after cessation of treatment. Overall, the growth rate was significantly slower in the chemotherapy-treated animals, resulting in diminished lean and fat mass, as well as significantly smaller skeletal muscles. Interestingly, 4 wk after cessation of the treatment, the animals exposed to chemotherapy showed persistent musculoskeletal defects, including muscle innervation deficits and abnormal mitochondrial homeostasis. Altogether, our data support that anticancer treatments may lead to long-lasting musculoskeletal complications in actively growing pediatric mice and support the need for further studies to determine the mechanisms responsible for these complications, so that new therapies to prevent or diminish chemotherapy-related toxicities can be identified.

Gross motor disorders in pediatric patients with acute lymphoblastic leukemia and survivors: A systematic review

Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children and toxicities related to treatment are common. One of these adverse effects is related to the musculoskeletal system and especially to gross motor skills that allow body movements: walking, running, jumping, and balance. This systematic review aims to describe gross motor impairments in pediatric patients with ALL during and after chemotherapeutic treatment and to identify the most commonly used tools for their assessment. Multiple electronic databases were searched for observational studies describing gross motor skills in children with ALL and the assessment tool used. The STROBE checklist was used to assess the reporting quality of each study. Ten studies were included in this review with assessments of gross motor skills in children with ALL undergoing treatment and survivors. Evidence suggests impairments in the performance of daily life activities during intensification and maintenance and persists up to 5 to 6 years after treatment´s cessation. Balance problems are noted at the start of treatment when the cumulative dose of vincristine is low and, in the survivors, it was the most reported alteration. These skills are essential for an adequate performance of children in daily life activities, recreation and leisure. We emphasize the need to assess gross motor skills and implement interventions that include physiotherapy and occupational rehabilitation in children with ALL.

Rehabilitation in children and adolescents undergoing stem cell transplantation: A pilot study focused on motor performance

OBJECTIVES

The aim of this pilot trial is evaluating the preliminary effectiveness of two in-hospital interventions in the maintenance of motor performance in children/adolescents undergoing hematopoietic stem cell transplantation (HSCT). Secondary objectives investigated the interventions' feasibility, impact on fatigue and to what degree the subjects' maintained their ankle dorsiflexion range of movement (ROM), functional mobility, muscle strength and flexibility.

METHODS

This trial included 5- to 18-year-old participants, affected by oncological and non-oncological diseases during hospitalisation for autologous/allogenic HSCT. The subjects were assigned to an exercise group (EG), or a counselling group based on a cluster model based on inpatient timeframe. The EG subjects performed strengthening, stretching and aerobic exercises for 30 min/5 days a week. Both groups followed rehabilitation counselling indications (RCI), 7 days a week.

RESULTS

Forty-nine participants were enrolled (median age = 12.9 years) (EG n = 36). In both groups the participants maintained their baseline motor performance and ankle ROM, and the children/adolescents and parents reduced their levels of fatigue. However, the interventions were not effective in maintaining strength.

CONCLUSION

In maintaining the subjects' motor performance, the RCI results are significant because they pave the way for the application in clinical practice contexts where there are poor rehabilitation resources. Clinical Trials registration NCT03842735.

Physical and functional performance assessment in pediatric oncology: a systematic review

BACKGROUND

Research indicates reduced physical performance from diagnosis into survivorship of pediatric cancer patients. However, there is no systematic information or guideline available on the methods to assess physical performance and function in this population. The purpose was to systematically compile and describe assessments of physical performance and function in patients and survivors of pediatric cancer, including cardiorespiratory fitness, muscle strength, speed, balance, flexibility, functional mobility, gait and motor performance test batteries.

METHODS

We searched the databases PubMed, SPORTDiscus, and Cochrane Database and performed abstract and full-text selection of 2619 articles according to the Cochrane Handbook of Systematic Reviews. Information on patients characteristics, assessments, information on validity and reliability, and relevant references was extracted.

RESULTS

In summary, 63 different assessments were found in 149 studies including 11639 participants. Most studies evaluated cardiorespiratory fitness and muscle strength with the majority conducted off treatment. Some outcomes (e.g. speed) and diagnoses (e.g. neuroblastoma) were severely underrepresented. With the exception of gait, leukemia patients represented the largest group of individuals tested.

CONCLUSIONS

Insufficient data and patient heterogeneity complicate uniform recommendations for assessments. Our results support researchers and practitioners in selecting appropriate assessment to meet their specific research questions or individual daily practice needs.

IMPACT

This systematic review includes 149 studies and provides a comprehensive summary of 63 assessments to evaluate cardiorespiratory fitness, muscle strength, speed, balance, flexibility, functional mobility, gait or motor performance test batteries in patients and survivors of pediatric cancer. We present the most studied fields within the pediatric cancer population, which are cardiorespiratory fitness and muscle strength, off treatment phase, and leukemia patients. We propose research priorities by identification of subgroups in terms of cancer type, phase of treatment, and outcome of interest that are underrepresented in studies currently available.

[Childhood Cancer Patients in a Family-Oriented Rehabilitation Program: Goals and Change in Physical Functioning]

PURPOSE

Childhood cancer often leads to physical and psychosocial burdens that can persist beyond the end of treatment. Family-oriented rehabilitation programs (FOR) focus on long-term consequences and support families in returning to daily life. The objectives of this study were to describe rehabilitation goals and goal attainment, to analyze the relationship between physical functioning and physical well-being and to examine predictors of changes in physical functioning during the FOR.

METHODS

In a prospective observational study, statements of physicians regarding rehabilitation goals, goal achievement and physical functioning of 175 children (<18 years of age at the time of diagnosis of leukemia or central nervous system tumor) at the beginning and the end of a FOR were analyzed. The physical well-being of the patients was assessed from a parent and child perspective. Correlation coefficients were calculated to analyze the relation between physical functioning and physical well-being. Predictors of changes in physical functioning were examined with a multiple regression analysis.

RESULTS

The most frequently mentioned rehabilitation goals were the increase of physical functioning and the integration into the peer group. Overall, the goal achievement ranged from 82 to 100%. Physical functioning improved significantly during the FOR. A significant positive correlation between the physician's assessment of physical functioning and the parental assessment of physical well-being could be found at the beginning of the FOR. According to the regression model, female gender of the child and a longer time since diagnosis were associated with a lower change in physical functioning. Furthermore, a higher degree of physical consequential damages was associated with a larger change.

CONCLUSIONS

The 4-week multimodal rehabilitation program of the FOR addressed various physical and psychosocial burdens and was accompanied by a significant improvement of the physical functioning of childhood cancer patients. The change in physical functioning was associated with different sociodemographic and medical factors (eg, sex). The consideration of these factors could help with optimizing the program.

Motor functioning and associated cognitive outcomes in pediatric survivors of acute lymphoblastic leukemia

Pediatric acute lymphoblastic leukemia survivors are at risk for developing neurocognitive late effects following intensive medical treatment. Motor impairments have been highlighted as a common neurocognitive late effect, including fine-, gross-, and visual-motor skills. The severity of these motor deficits is variable in the existing literature, warranting additional investigations with more homogenous samples. In addition, there is an even greater paucity regarding the interrelations between motor deficits and the impact motor challenges may have on other domains of functioning, such as academics. Therefore, the present study aimed to characterize motor functioning in children who were treated for acute lymphoblastic leukemia with chemotherapy (n = 13) in comparison to healthy controls (n = 13). Additionally, this study investigated the relationship between primary (e.g., visual-spatial, fine-motor), secondary (e.g., visual-motor), and tertiary (e.g., academics) skills. The results revealed that oncology survivors had significantly lower fine- and gross-motor skills compared to healthy controls. No significant differences were observed between the groups on visual-perception and visual-motor tasks. Fine-motor functioning was significantly associated with visual-motor functioning in ALL survivors. Motor skills were not related to academic outcomes. The present findings provide evidence for motor impairments in pediatric ALL survivors, along with initial findings highlighting the cascading effect of primary motor impairments on other cognitive domains. This research sheds light on the need for clinical screening and intervention of motor skills in the survivorship population. Future research is warranted to examine the effect of motor deficits on cognitive and psychosocial functioning in pediatric oncology.

Whole-body vibration in children with disabilities demonstrates therapeutic potentials for pediatric cancer populations: a systematic review

PURPOSE

Low levels of physical activity often observed in pediatric oncology might be attributed to various functional deficits, especially those of the lower limbs as these affect gait, mobility, and, consequently, physical activity. In the past few years, whole-body vibration (WBV) has emerged as a new therapy modality for improving physical functioning. Although WBV is increasingly applied in children with disabilities, its impact on lower limb function in pediatric cancer patients and survivors has not yet been investigated.

METHODS

To establish whether there is evidence that WBV may be beneficial for pediatric cancer patients and survivors, this review summarizes current data on WBV studies among children with disabilities and extracts relevant information for the pediatric cancer population. Two independent reviewers performed a systematic literature search following the PRISMA guidelines.

RESULTS

Nine studies were included in the analysis. Results demonstrate that WBV is a safe, highly compliant, and effective approach in cohorts of children with disabilities. The largest effects of WBV were observed in lower extremity muscle mass and strength, balance control, gait, and walking ability. Furthermore, we were able to develop first recommendations for WBV protocols.

CONCLUSIONS

WBV seems to be feasible and effective for improving parameters that may be relevant to the pediatric cancer population. Efforts are needed to conduct first WBV interventions in children with cancer proving the effects. The developed recommendations for WBV protocols might help to implement these intervention studies.

Impact of the initial fitness level on the effects of a structured exercise therapy during pediatric stem cell transplantation

BACKGROUND

Before and after hematopoietic stem cell transplantation (HSCT), most patients suffer from psychophysical limitations due to the treatment. Exercise interventions demonstrate beneficial effects on, for example, strength, endurance, or health-related quality of life during and after HSCT, but with a great variation among patients concerning the response to exercise. This study examines the influence of the initial fitness on the effects of an exercise therapy in pediatric HSCT.

PROCEDURE

Fifty-three children and adolescents (10.9 ± 3.5 years) scheduled for HSCT were randomized into an exercise intervention group (IG) or a control group (CG). During hospitalization, the IG performed endurance, strength, and flexibility training three times per week. The CG included a nonexercise program. A 6-min walk test was completed before and after the inpatient period. Baseline results (6-min walking distance [6MWD]) were used to split both groups into the following: IG_UNFIT , n = 14; IG_FIT , n = 12; CG_UNFIT , n = 16; CG_FIT , n = 11. Differences in outcome changes between groups were analyzed with H-test.

RESULT

Intergroup comparison revealed significant differences between IG_UNFIT and CG_UNFIT (P < 0.05). The IG_UNFIT increased their 6MWD by +8% (vs. IG_FIT , +1%); both CGs presented a decline in 6MWD (CG_UNFIT , -14%; CG_FIT , -16%). At discharge, the IG_FIT achieved 85.5 ± 10.3% of healthy reference values.

CONCLUSIONS

The current results indicate that exercise during pediatric HSCT is feasible and contributes to prevention of treatment-related loss of physical function. As seen in healthy persons, patients' benefits might depend on their initial fitness level. As a diminished physical capability may result in higher training effects, impaired especially patients should engage in exercise.

Objectively measured versus self-reported physical activity in children and adolescents with cancer

Objective

Existing research recognizes low levels of physical activity in pediatric patients with cancer, but much uncertainty exists about their capability to self-reflect physical activity levels. The objective of this study was to compare results of subjective self-reports and objective accelerometers regarding levels of daily walking as well as moderate-to-vigorous physical activities.

Methods

Results of the objective assessment tool StepWatchTM Activity Monitor and self-reporting with a standardized questionnaire were compared in 28 children and adolescents during cancer treatment.

Results

The patients were 13.8±2.8 years of age and 3.4±2.0 months after cancer diagnosis. The Bland-Altman plots indicated a fairly symmetrical under- and over-estimation for daily minutes of walking with the limits of agreement ranging from -100.8 to 87.3 min (d = -6.7 min). Mean difference for moderate-to-vigorous physical activity was almost zero but limits of agreement are ranging from -126.8 to 126.9 min. The comparison for the days with at least 60 min of moderate-to-vigorous physical activity showed a marked difference with 3.0±2.6 self-reported days versus only 0.1±0.4 measured days.

Conclusions

These findings suggest that physical activity in pediatric cancer patients should preferably be assessed with objective methods. Greater efforts are needed to implement supervised exercise interventions during treatment incorporating methods to improve self-reflection of physical activity.

Short-term recovery of chemotherapy-induced peripheral neuropathy after treatment for pediatric non-CNS cancer

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent side effect of pediatric cancer treatment. The presentation of CIPN, trajectory and completeness of recovery over the first 6 months postchemotherapy, and the influence of patient and treatment characteristics on recovery are described.

PATIENTS AND METHODS

Sixty-seven children and adolescents treated for non-CNS cancers were evaluated for CIPN using the pediatric modified total neuropathy score (ped-mTNS) while on treatment and 3 and 6 months postchemotherapy. Differences between diagnostic groups and treatment type were evaluated as well as change in scores over time. Risk factors for on-treatment and persistent CIPN at 6 months were identified.

RESULTS

Overall, ped-mTNSs were in the abnormal range for 86.5% during treatment and scores decreased over time (initial 9.3 ± 0.6, 6 months 4.3 ± 0.4; F = 38.14, P < 0.001). By 6 months posttreatment, mean scores and percentage of children with abnormal scores were reduced to 2.4 ± 0.3 and 11.5%, respectively, in the ALL group, but remained higher at 5.7 ± 0.7 and 57%, respectively, for lymphoma, and 5.2 ± 1.0 and 60%, respectively, for other solid tumors. At 6 months posttreatment, light touch deficits and foot strength deficits remained in 19.4 and 59.7%, respectively, compared with only 4.9 and 9.8% of the control population. Subjects who were older at exposure, female, or who received etoposide in addition to vincristine were at higher risk for on-treatment CIPN. On-treatment sensory abnormalities were associated with increased risk of persistent CIPN.

CONCLUSION

While CIPN improves in most pediatric patients, significant numbers, especially those treated for lymphoma or other solid tumors, have remaining neuropathic signs and symptoms 6 months posttreatment.

Impairments of Lower Extremity Muscle Strength and Balance in Childhood Cancer Patients and Survivors: A Systematic Review

This review aims to summarize the evidence for impairments of muscle strength and balance during and after treatment for childhood cancer. Thirty-two articles, identified in scientific databases by means of a structured search for investigations of muscle strength and balance in pediatric cancer patients and survivors, are evaluated. A summary of results is given with respect to matching reporting items to provide a qualitative analysis of the evidence. The majority of the studies reached a level 3 rating according to Oxford Centre for Evidence-Based Medicine (OCEBM) 2011 levels of evidence. Muscle strength and balance seem to be impaired in varying degrees depending on the diagnosis, treatment received, and time elapsed between treatment and evaluation. Drawing specific conclusions from the identified studies is difficult because of heterogeneous study samples and methods of research. Individual targeted exercise therapy programs during treatment and follow-up of childhood cancer could help to prevent and further diminish impairments of muscle strength and balance function among childhood cancer patients and survivors.

Physical activity and health-related quality of life in pediatric cancer patients following a 4-week inpatient rehabilitation program

PURPOSE

Chronic health conditions and impaired quality of life are commonly experienced in childhood cancer survivors. While rehabilitation clinics support patients in coping with the disease, studies evaluating an inpatient rehabilitation program on promoting physical activity (PA) and health-related quality of life (HRQoL) are missing.

METHODS

A 4-week inpatient rehabilitation program was prospectively evaluated. One hundred fifty patients with leukemia or lymphoma (N = 86), brain tumors (N = 38), and sarcomas (N = 26) were enrolled on average 17 months after cessation of acute medical treatment. PA amount and cadence (indicating the intensity of walking activity) using the StepWatch™ 3 Activity Monitor and HRQoL global and physical well-being scores using the KINDL(®) questionnaire were assessed before, immediately after, and 6 and 12 months following the program and analyzed using multiple linear mixed models.

RESULTS

Significant effects on PA were only found at 12-month follow-up for amount and cadence variables (all p < 0.05). While leukemia and lymphoma patients revealed the highest PA level throughout the study, rehabilitation effects were more pronounced for cadence variables in brain tumor and sarcoma patients. The rehabilitation program had immediate (t = 4.56, p < 0.001) and sustainable effects on HRQoL global scores (6-month follow-up, t = 4.08, p < 0.001; 12-month follow-up, t = 3.13, p < 0.006).

CONCLUSIONS

Immediate and sustainable increases in HRQoL indicate that a 4-week rehabilitation program is beneficial for improving psychosocial well-being, while the significant increase in PA levels could be related to general recovery as well. The lack of a control group hampers the evaluation of the rehabilitation program on promoting PA levels in pediatric cancer patients.

Physical activity and health-related quality of life in pediatric cancer patients following a 4-week inpatient rehabilitation program

PURPOSE

Chronic health conditions and impaired quality of life are commonly experienced in childhood cancer survivors. While rehabilitation clinics support patients in coping with the disease, studies evaluating an inpatient rehabilitation program on promoting physical activity (PA) and health-related quality of life (HRQoL) are missing.

METHODS

A 4-week inpatient rehabilitation program was prospectively evaluated. One hundred fifty patients with leukemia or lymphoma (N = 86), brain tumors (N = 38), and sarcomas (N = 26) were enrolled on average 17 months after cessation of acute medical treatment. PA amount and cadence (indicating the intensity of walking activity) using the StepWatch™ 3 Activity Monitor and HRQoL global and physical well-being scores using the KINDL(®) questionnaire were assessed before, immediately after, and 6 and 12 months following the program and analyzed using multiple linear mixed models.

RESULTS

Significant effects on PA were only found at 12-month follow-up for amount and cadence variables (all p < 0.05). While leukemia and lymphoma patients revealed the highest PA level throughout the study, rehabilitation effects were more pronounced for cadence variables in brain tumor and sarcoma patients. The rehabilitation program had immediate (t = 4.56, p < 0.001) and sustainable effects on HRQoL global scores (6-month follow-up, t = 4.08, p < 0.001; 12-month follow-up, t = 3.13, p < 0.006).

CONCLUSIONS

Immediate and sustainable increases in HRQoL indicate that a 4-week rehabilitation program is beneficial for improving psychosocial well-being, while the significant increase in PA levels could be related to general recovery as well. The lack of a control group hampers the evaluation of the rehabilitation program on promoting PA levels in pediatric cancer patients.

Effects of a 6-Month, Group-Based, Therapeutic Exercise Program for Childhood Cancer Outpatients on Motor Performance, Level of Activity, and Quality of Life

BACKGROUND

Exercise interventions in pediatric oncology are feasible and safe. However, scarce data are available with regard to the effectiveness of outpatient, group-based exercise interventions. As well, the potential role of exercise to improve motor performance has not been adequately explored despite being a meaningful outcome during childhood with important implications for physical activity behavior. No study has yet demonstrated significant changes in motor performance after an exercise intervention.

PROCEDURES

This explorative, prospective study was designed to evaluate the effects of a 6-month, group-based, therapeutic exercise program for a mixed childhood cancer population on motor performance, level of activity, and quality of life. After cessation of inpatient medical treatment, childhood cancer outpatients aged 4-17 years exercised once a week during a 6-month period (IG). Comparison groups included childhood cancer outpatients receiving care as usual (CG(1)), as well as healthy peers (matched to IG by age and gender) (CG(2)).

RESULTS

Overall motor performance, various motor dimensions, activity in sport clubs and school sports, as well as physical and emotional well-being were significantly reduced in the IG at baseline. Significant differences between the IG and CG(1) and/or CG(2) were identified in the change of overall motor performance, single motor dimensions, overall level of activity, and emotional well-being from baseline to post-intervention.

CONCLUSIONS

The exercise intervention was beneficial in terms of motor performance, level of activity, and emotional well-being. As such, this study provides support for group-based exercise as a potential strategy to improve these outcomes after inpatient medical treatment.

Motor Performance After Treatment for Pediatric Bone Tumors

BACKGROUND

Reduced motor performance can negatively affect physical activity and social partake after childhood cancer. Especially in bone tumor patients, who are at risk of physical limitations due to surgical interventions, motor performance has not yet been sufficiently investigated. Therefore, this study aimed at assessing motor performance in pediatric bone tumor patients.

PROCEDURE

Motor performance was measured within 2 years posttreatment using the MOON (test for MOtor performance in pediatric ONcology) test. This instrument enables quantitative data collection even in physically impaired patients for comparison with age-matched and sex-matched reference values.

RESULTS

Twenty-one patients (13 male) ages 15.2±2.1 years (median: 15 y, 10 to 19 y) and 9.4±7.4 months posttreatment (median: 6 mo, 2 to 24 mo) were tested. Motor performance was slightly reduced in muscular endurance of the legs; significantly reduced in speed, flexibility, eye-hand coordination, and muscular explosive strength (P<0.001), whereas patients' hand grip strength and static balance were superior to the reference values. Follow-up duration, body mass index, and tumor localization apparently affected motor performance.

CONCLUSIONS

These findings show serious reductions in motor performance within 2 years after bone tumor treatment and highlight the need for interventions to improve motor performance. The results should be used to advise and support patients to engage in suitable physical and sports activities.

Motor performance in children and adolescents with cancer at the end of acute treatment phase

Reduced motor performance may particularly limit reintegration into normal life after cessation of treatment in pediatric cancer patients. This study aimed at analyzing motor performance at the end of the acute treatment phase and reveals potential risk factors for motor deficits. A childhood cancer population with different tumor entities was assessed with the MOON test, which allows for comparison with age- and gender-matched reference values of healthy children, at the end of the acute treatment phase. Forty-seven patients were tested at 7.0 ± 2.6 months after diagnosis. Significant reductions of motor performance affected muscular explosive strength (P < 0.001), handgrip strength (P < 0.001), muscular endurance of legs (P = 0.035), hand-eye coordination (P < 0.001), static balance (P = 0.003), speed (P = 0.012), and flexibility (P < 0.001). Loss of upper extremity coordination did not achieve statistical significance. Associations between single motor deficits and the tumor entity, age, body mass index, and inactivity during treatment were revealed, whereas no associations were found for gender and vincristine application.

CONCLUSION

Overall, motor performance was low in the patient group studied. We recommend that individualized exercise interventions to attenuate motor deficits and promote physical activity are needed during cancer treatment in order to enhance motor performance and improve social participation during and after cancer therapy.

Die Überprüfung der Konstruktvalidität des Deutschen Motorik-Tests 6-18 für 9- bis 10-Jährige

Für den aus 8 Items bestehenden Deutschen Motorik-Test 6-18 ( Bös et al., 2009 ) konnte bislang weder ein eindimensionales noch zweidimensionales (Koordination/Kondition) Strukturmodell bestätigt werden. Anhand probabilistischer (Mixed-Rasch-Modell) und klassischer (konfirmatorische Faktorenanalyse) Testmodelle wird geprüft, ob von Bös et al. (2009) empfohlene Normkategorien oder eine alternative Kategorisierung empirische Validität besitzen. Im Kreuzvalidierungsdesign werden für 9 – 10-Jährige mittels zweier Stichproben (N 1 = 1495, N 2 = 1357; 49,2 % weiblich) Analysen mit den Norm-Quintilen und Z-normierten Norm-Leistungsklassen sowie Standardnoten nach T-Transformation der empirischen Daten (eT-Kategorien) durchgeführt. Die Konstruktvalidität bezüglich der beiden publizierten Normkategorisierungen kann nicht nachgewiesen werden. Demgegenüber ergibt die Analyse der eT-Kategorisierung eine Ein-Klassen-Lösung des Mixed-Rasch-Modells, wobei theoriekonform „Rumpfbeuge“ und aufgrund lokaler Modellverletzungen „Balancieren rückwärts“ auszuschließen sind. Die faktorielle Validität dieses eindimensionalen Modells wird bestätigt. Für 9 – 10-Jährige kann demnach Homogenität bezüglich eines eindimensionalen Motorik-Index (mit sechs Items) angenommen werden. Dieser Motorik- resp. Fitness-Index kann aus den sechs homogenen Items gebildet werden und ist für sportmotorische Testungen valide interpretierbar.