Enhancing hand function in patients with hematologic malignancies: a novel knitted glove approach

Abstract

[Purpose] Patients with hematologic malignancies frequently experience hand function decline due to disease progression and adverse effects of chemotherapy and hematopoietic stem cell transplantation. Given the critical importance of daily hand function, effective rehabilitation strategies are essential. This study evaluated the feasibility and safety of a novel knitted hand function enhancement glove designed for routine use. [Participants and Methods] Six hospitalized patients undergoing chemotherapy or bone marrow transplantation voluntarily participated by wearing gloves and recording wear time. Functional assessments, including grip strength, pinch strength, and the Box and Block Test, were performed at baseline and at 1 and 2 weeks post-intervention. [Results] Adverse events occurred in less than 5% of patients and comprised mild skin irritation and temporary numbness. A significant improvement was observed in the Box and Block Test after wearing hand function enhancement gloves, whereas grip strength and pinch strength showed no significant changes. Compliance was strongly correlated with functional improvement, suggesting a potential role of the glove in passive rehabilitation. [Conclusion] This knitted glove may serve as a practical, low-impact rehabilitation tool for safely maintaining finger dexterity during hospitalization. Further investigation is warranted to evaluate its long-term efficacy.

INTRODUCTION

Patients with hematologic malignancies are known to experience a decline in hand strength due to underlying primary diseases and side effects of treatments, such as hematopoietic stem cell transplantation and chemotherapy. Hand function is associated with daily activities and is essential for tasks such as opening bottles or fastening buttons; therefore, functional changes in the hands can markedly affect the quality of life. Rehabilitation exercises, such as hand grip training, are commonly prescribed for patients with diminished hand function. However, these approaches require active patient participation, which may be challenging for individuals experiencing treatment-related side effects from procedures such as hematopoietic stem cell transplantation and chemotherapy.

Although wearable devices for independent training exist, most are made of metals and require a considerable time commitment. Their long-term use has been associated with adverse effects, such as tingling sensations, numbness, and discoloration of the fingertips, raising concerns about their safety and sustainability. Moreover, because these devices are metallic, users often find it difficult to perform daily activities without being constantly conscious, highlighting the need for training methods that can be safely implemented over extended periods.

To address these issues, this study utilized a “hand-function enhancement glove”, a knitted product made by specifically sewing elastic threads together, making it lighter and safer than metal-based products¹⁾ (Fig. 1). The glove is designed to curve back toward the dorsum of the hand, a feature reported to contribute to the strengthening of finger flexor muscles. Notably, it can be worn during daily activities, allowing users to train their hand functions without consciously focusing on the training itself. By wearing this glove, patients with hematologic malignancies may safely engage in long-term hand function training as part of their daily routines.

Fig. 1.

A glove designed to enhance hand functionality, sewn together with stretchable thread using a unique method. This glove has a structure that curves on the back of the hand.

Previous studies in healthy individuals have suggested that wearing hand-function enhancement gloves can safely improve hand function in daily life. Consequently, this study aimed to examine the feasibility, safety, and efficacy of long-term use of these training-friendly knitted gloves in patients with hematologic malignancies. We hypothesized that the gloves would be safe to wear during hospitalization and would help maintain hand strength.

PARTICIPANTS AND METHODS

This study examined the safety and efficacy of finger function enhancement gloves during hospitalization in patients with hematologic malignancies undergoing chemotherapy or hematopoietic stem cell transplantation. The main inclusion criteria were as follows: 1) age between 20 and 90 years, and 2) planned hospitalization in a protective isolation room for treatment lasting more than 2 weeks. The exclusion criteria were as follows: 1) history of cerebrovascular accident, spinal cord disorder, or finger functional paralysis due to peripheral neuropathy, 2) presence of neurological or muscular disease, 3) absence of cognitive impairment, 4) inability to answer questionnaires, 5) ongoing treatment for severe heart failure or respiratory disease, 6) pregnancy, 7) history of surgical treatment within the past 48 weeks or current use of therapeutic drugs not approved in Japan, and 8) being deemed inappropriate for inclusion in this study by the researchers.

The study was conducted from January 2025 to March 2025 after receiving approval from the Ethics Committee of Nara Prefectural General Medical Center (Approval No. 959). All procedures adhered to the ethical standards of the institutional and/or national research committee and to the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The principal investigator and co-investigator provided participants with consent and withdrawal forms approved by the ethical review board, along with comprehensive written and verbal explanations. Written informed consent was obtained from all participants included in the study. Participation was voluntary, and participants were informed of their right to withdraw at any time without any consequences.

The rehabilitation program using finger function enhancement gloves was simple. Participants were instructed to wear this glove whenever possible during hospitalization. They were allowed to remove them at their discretion, such as during bathing or handwashing, and were asked to record their daily wear time. Participants who consented to enroll in the study wore hand function enhancement gloves (Mikasa Co., Ltd., Yokohama, Japan) during their hospital stay. Questionnaire surveys were conducted to evaluate dysfunction, adverse events, and compliance. Grip strength and pinch strength were measured at three time points: baseline, 1 week after intervention (T1), and 2 weeks after intervention (T2). The Box and Block Test was performed at two time points: baseline and last evaluation. All physical function and safety assessments were conducted by a blinded evaluator.

Patient safety was monitored through interviews and physical examinations. The incidence of adverse events was calculated by dividing the number of days on which an adverse event occurred by the number of days the device was worn, with a low incidence of adverse events defined as less than 5%. A recent systematic review and device-specific assessment showed that mild adverse events, such as skin irritation and muscle pain, occurring in less than 5% of users are clinically acceptable and indicate a high level of device safety^2,3,4).

A digital grip strength meter (TKK5401 SANKA Co., Ltd., Niigata, Japan) was used to measure grip strength. In a standing or sitting position, the participants held the grip strength meter such that the proximal interphalangeal joint of the index finger formed a right angle. Measurements were taken twice on each hand, alternating between the left and right. Additionally, a pinch meter (ST-1023, OG Wellness, Okayama, Japan) was used to measure pinch strength. In the sitting position, two types of pinch strengths—tip pinch and lateral pinch—were measured twice on each hand, alternating between the left and right sides. A 1-min break was allowed between measurements. In the simplified upper limb function test, the participants moved objects of various sizes and shapes in a sitting position using a measuring device (Sakai Medical Co., Ltd. Tokyo, Japan), and the total score for both hands was calculated.

Wearing time and adverse events after wearing the hand function enhancement gloves were confirmed through a questionnaire survey. For each hand function evaluation, measurements obtained at baseline, T1 (1 week), and T2 (2 weeks) were compared using the Wilcoxon signed rank sum test, with statistical significance set at p<0.05. We evaluated the normality of the data distribution using the Shapiro–Wilk test, which indicated a non-normal distribution, thereby justifying the use of non-parametric tests. We calculated the Spearman correlation coefficient (r_s) to assess the association between compliance and motor function. Based on the r_s-value, the correlations were classified as moderate (r_s=0.40–0.54) or strong (r_s=0.55–1.00). Statistical analyses were performed using SPSS software (version 25.0; IBM, Armonk, NY, USA).

RESULTS

Nine patients with hematologic malignancies were recruited, of whom six (three females and three males) participated in this study (Table 1). Two patients had acute myeloid leukemia, two had chronic myeloid leukemia, and two had malignant lymphoma. All patients were independent in their original activities of daily living and had preserved cognitive function. During the intervention period, one patient developed skin symptoms, and another complained of numbness from the back of the hand to the forearm. All adverse events were resolved by the day after the intervention, and no additional adverse events were observed. The frequency of adverse events was low, demonstrating the safety of these gloves.

Table 1. Patient characteristics.

	Age	Sex	Diagnosis	Treatment	Comorbidity	Grip strength (kg)	Tip pinch strength (kg)	Lateral pinch strength (kg)	Box and block test (number of blocks moved)
P1	71	Male	Acute myeloid leukemia	Chemotherapy	Diabetes	23.4	4.1	6.2	31.5
P2	82	Male	Acute myeloid leukemia	Chemotherapy	Hyperlipidemia/Diabetes	15.0	5.6	6.1	36.0
P3	74	Female	Malignant lymphoma	Chemotherapy	Diabetes	15.7	2.6	5.2	39.5
P4	71	Female	Malignant lymphoma	Chemotherapy	Osteoporosis	16.2	3.0	4.7	54.0
P5	39	Female	Chronic myeloid leukemia	Bone marrow transplantation	None	28.6	5.3	7.7	40.0
P6	83	Male	Chronic myeloid leukemia	Chemotherapy	Internal carotid artery stenosis/Hypertension	13.1	3.5	6.2	43.0

P: patient.

After 1 week of device use, grip strength (p=0.753), tip pinch strength (p=0.686), and lateral pinch strength (p=0.786) showed no significant improvement. When data from patients who wore the device for 2 weeks were included in the analysis, a significant improvement was observed in the Box and Block Test (p=0.043). However, grip strength (p=0.600), tip pinch strength (p=0.686), and lateral pinch strength (p=0.786) did not improve (Fig. 2A–2D). Additionally, no correlation was found between initial grip strength and degree of improvement.

Fig. 2.

Longitudinal changes in finger dexterity before and after wearing finger function enhancement gloves in six participants with hematologic malignancies. (A) Grip strength, (B) tip pinch strength, (C) lateral pinch strength, and (D) Box and Block Test. Median values: (A) T0: 15.9, T1: 18.0, T2:18.4, (B) T0: 3.3, T1: 3.6, T2:3.7, (C) T0: 5.3, T1: 5.3, T2: 5.3, (D) T0: 41.3, T1 and T2: 51.8. T0; before intervention, T1;1 week after intervention, T2; 2 weeks after intervention. Data at T1 were available for six participants, and at T2 for four participants.

The duration of wearing the gloves showed a strong correlation with the degree of improvement in grip strength (r=0.429) and the Box and Block Test (r=0.486). No correlation was observed between tip pinch strength (r=0.086) and lateral pinch strength (r=0.086).

DISCUSSION

This study examined the safety and efficacy of the “hand function enhancement glove” in patients with hematologic malignancies. The results showed significant improvements in Box and Block Test scores, indicating a measurable degree of finger dexterity⁵⁾. These findings suggest that wearing the gloves helps maintain and improve certain aspects of hand function, which contradicts the expectation of overall hand function enhancement.

Previous studies have reported the effectiveness of hand function enhancement devices in healthy individuals and patients with Parkinson’s disease^{6, 7)}. However, this is the first report on a knitted hand function enhancement device. Patients with hematologic malignancies often experience muscle weakness and sensory abnormalities due to chemotherapy and hematopoietic stem cell transplantation; similar symptoms were observed in this study population⁸⁾. Given that treatment-induced fatigue and sensory abnormalities are critical concerns, the development of low-burden rehabilitation tools is essential⁹⁾. The present findings highlight the glove’s potential clinical utility, necessitating further investigation into its long-term usability.

A strong correlation was observed between glove-wearing duration and improvements in the grip strength and Box and Block Test scores. The improvement in finger dexterity suggests that the resistance provided by the glove may have facilitated activity in the finger flexor muscle^{10, 11)}. Furthermore, the improvement in the Box and Block Test indicates enhanced muscle strength and functional coordination. Conversely, no clear improvement trends were observed in the pinch strength, suggesting that the structural characteristics of the glove may limit its efficacy on specific muscle groups. Previous literature has reported the MCID for BBT to be between 5.29 and 6.46 blocks, with an improvement of 7 blocks or more recommended as clinically significant. However, in this study, only two patients (P3 and P4) achieved an improvement of 7 blocks or more. While finger dexterity may be maintained, longer-term observation is needed to determine whether it can be further improved¹²⁾. Future studies should incorporate different hand-function assessment metrics for comprehensive evaluation. Recent studies have shown that finger function enhancement devices using soft robotic technology may improve finger dexterity in patients with neuromuscular diseases¹³⁾. These devices, like the gloves used in this study, share a common feature of being wearable for extended periods, and there is a demand for devices that can be used for longer durations. This knitted device is lightweight and easy to use, making it highly versatile for prolonged use.

The limitations of this study include its small sample size and relatively short observation period. Although the reported correlation coefficients were moderate, the small sample size limits confidence in these findings. The small sample size of this study limited statistical power and may result in overestimation. In this study, compliance was assessed using self-reported wearing time, which may have introduced recall bias. Future studies should consider using wearable sensors to enhance the objectivity of the results. Notably, some patients in this study showed no improvement, and some worsened, suggesting the presence of both responders and non-responders. Larger studies are required to clarify the optimal conditions for using hand function enhancement gloves in patients with hematologic malignancies.

Funding

This study received no specific grants from any funding agency in the public, commercial, or not-for-profit sectors.

Conflict of interest

The authors state that they have no conflicts of interest.

Data availability

The data that support the findings of this study are available on request from the corresponding author.