Postural control skills, proprioception, and risk of fall in long-term survivor patients treated with knee rotationplasty

Assessment of Balance During a Single-Limb Stance Task in Healthy Adults: A Cross-Sectional Study

Single-limb stance (SLS) is a demanding postural task, widely used for balance assessment in both research and clinical practice. Despite extensive data on elderly and clinical populations, less is known about younger and healthier adults. Our aim in this study was to assess balance during a SLS task among a cohort of healthy adults to determine whether there are age or sex group or testing condition differences in performances. In this cross-sectional study, we involved 120 participants aged 30-65 years and divided them into four age sub-groups with equal numbers of males and females in each. We assessed balance during a 45-s SLS task on a] the Delos Postural Proprioceptive System for both lower limbs in two conditions - open eyes (OE) and closed eyes (CE). We calculated stability (SI) and autonomy (AU) indices and used analysis of variance to determine that there was no significant effect of limb dominance or sex on balance parameters. However, there was a significant interaction effect between age group and testing condition for both SI and AU (p < .001 for both), with balance worsening as age increased only in the CE condition. These results highlight a pattern of balance decline with age when vision is eliminated from balance performance, underscoring the critical relationship between sensory input and postural control as people age.

Quantitative methods used to evaluate balance, postural control, and the fear of falling in lower limb prosthesis users: A systematic review

Problems with balance, postural control, and fear of falling are highly prevalent in lower limb prosthesis users, with much research conducted to understand these issues. The variety of tools used to assess these concepts presents a challenge when interpreting research outcomes. This systematic review aimed to provide a synthesis of quantifiable methods used in the evaluation of balance, postural control, and fear of falling in lower limb prosthesis users with an amputation level at or proximal to the ankle joint. A systematic search was conducted in CINAHL, Medline, AMED, Cochrane, AgeLine, Scopus, Web of Science, Proquest, PsycINFO, PsycArticles, and PubPsych databases followed by additional manual searching via reference lists in the reviewed articles databases. Included articles used quantitative measure of balance or postural control as one of the dependent variables, lower limb prosthesis users as a sample group, and were published in a peer-reviewed journal in English. Relevant assessment questions were created by the investigators to rate the assessment methods used in the individual studies. Descriptive and summary statistics are used to synthesize the results. The search yielded (n = 187) articles assessing balance or postural control (n = 5487 persons in total) and (n = 66) articles assessing fear of falling or balance confidence (n = 7325 persons in total). The most used test to measure balance was the Berg Balance Scale and the most used test to measure fear of falling was the Activities-specific Balance Confidence scale. A large number of studies did not present if the chosen methods were valid and reliable for the lower limb prosthesis users. Among study limitations, small sample size was common.

Muscle synergies for the control of single-limb stance with and without visual information in young individuals

Purpose

Single-limb stance is a demanding postural task featuring a high number of daily living and sporting activities. Thus, it is widely used for training and rehabilitation, as well as for balance assessment. Muscle activations around single joints have been previously described, however, it is not known which are the muscle synergies used to control posture and how they change between conditions of normal and lack of visual information.

Methods

Twenty-two healthy young participants were asked to perform a 30 s single-limb stance task in open-eyes and closed-eyes condition while standing on a force platform with the dominant limb. Muscle synergies were extracted from the electromyographical recordings of 13 muscles of the lower limb, hip, and back. The optimal number of synergies, together with the average recruitment level and balance control strategies were analyzed and compared between the open- and the closed-eyes condition.

Results

Four major muscle synergies, two ankle-dominant synergies, one knee-dominant synergy, and one hip/back-dominant synergy were found. No differences between open- and closed-eyes conditions were found for the recruitment level, except for the hip/back synergy, which significantly decreased (p = 0.02) in the closed-eyes compared to the open-eyes condition. A significant increase (p = 0.03) of the ankle balance strategy was found in the closed-eyes compared to the open-eyes condition.

Conclusion

In healthy young individuals, single-limb stance is featured by four major synergies, both in open- and closed-eyes condition. Future studies should investigate muscle synergies in participants with other age groups, as well as pathological conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-021-00392-z.

[Application of rotationplasty in treatment of osteosarcoma of distal femur in children]

OBJECTIVE

To investigate the effectiveness of rotationplasty in treating osteosarcoma of distal femur in children.

METHODS

A clinical data of 10 children with osteosarcoma of distal femur treated with rotationplasty between March 2014 and June 2016 was retrospectively analyzed. There were 7 boys and 3 girls with an average age of 6.7 years (range, 4-10 years). There were 4 cases of osteoblastic osteosarcoma, 4 cases of mixed osteosarcoma, and 2 cases of chondroblastic osteosarcoma. All children were staged as Enneking stage ⅡB. The disease duration ranged from 3.5 to 6.0 months (mean, 4.6 months). The lower limb functional scoring system of 1993 Musculoskeletal Tumor Society (MSTS93), Toronto Extremity Salvage Score (TESS), and knee mobility were used to evaluate postoperative function. Tumor recurrence and metastases were monitored by radiograph.

RESULTS

Poor superficial incision healing occurred in 1 patient, and healed after dressing change. The other incisions healed by first intention. All children were followed up 24-72 months (mean, 52.6 months). No local recurrence was observed during follow-up. Three of the ten patients suffered from metastases including 1 dying of multiple organ dysfunction syndrome, 1 alive with tumor, and 1 tumor free survival. Painful callosities and ulcers which related to prosthetic wear occurred in 2 patients and turned up after optimizing prosthetic fit and physiotherapy. The fracture healing time was 2.5-5.0 months (mean, 3.5 months). All children could walk independently at 4 months postoperatively. At last follow-up, the MSTS93 score was 19-25 (mean, 22) and the TESS score was 87-93 (mean, 90). The extension of knee joint mobility with artificial limbs was 0°-10° (mean, 5°), and the flexion of knee joint mobility with artificial limbs was 85°-95° (mean, 90.5°).

CONCLUSION

Rotationplasty in treating osteosarcoma of distal femur in children with limb salvage difficulties can effectively preserve the limb function and improve the quality of life, and it can be used as an alternative to amputation.