Plantarflexion strength of the toes: age and gender differences and evaluation of a clinical screening test

A 3 month nutrition and exercise program improved hallux strength among senior daycare center users in Korea: a cluster randomized controlled trial

Introduction

With a growing aging population, the focus on the health and well-being of older adults, especially in preventing falls, becomes crucial. This 3 month study, initiated in July 2022, aimed to assess the impact of a nutrition and exercise program in senior daycare centers in Chuncheon, South Korea.

Methods

A 3 month study, beginning in July 2022, included 204 older adults from 10 senior daycare centers in Chuncheon, South Korea. Randomly assigned to intervention or control groups, the intervention involved nutrition, daily toe exercises, or both. Control centers received interventions post-measurements. Pre- and post-intervention analyses used paired t-tests and multiple linear regression, assessing metrics like toe grip strength for significance. While 204 were initially enrolled, the analysis included 151 participants due to dropouts.

Results

Participants, with a mean age of 83.3 years (43.1% aged ≥ 85 years), exhibited mild to moderate cognitive impairment and multiple chronic illnesses. Health data indicated that 37.3% were obese, and the average BMI was 24.0 kg/m2. Both the intervention and control groups showed significant improvements in toe grip strength post-intervention. Specifically, the exercise-only and combined exercise-nutrition groups demonstrated significant differences in hallux strength compared to the control group after adjusting for age and gender.

Conclusion

The study showed that a basic nutrition and exercise program increased toe strength in older adults with chronic diseases, including mild cognitive impairments. This intervention holds potential to prevent muscle strength decline and reduce fall risks in older individuals. As the first of its kind in Korean senior daycare centers, it emphasizes the need for future research and standardized programs for senior daycare users.

Age-Related Reduction of Foot Intrinsic Muscle Function and the Relationship with Postural Stability in Old Adults

Introduction

The risk of falls among the elderly significantly increases, which has become a serious public health concern. Falls can not only lead to serious complications such as fractures and brain injuries but also limit their mobility function, reducing quality of life. Foot intrinsic muscles (FIMs) are an essential part of foot core stability even overall postural stability. This study aimed to investigate the effects of aging on the function of FIMs and to explore the influence of FIMs on postural control in the elderly.

Materials and Methods

56 healthy old participants (60-75 years) and 57 healthy young participants (18-29 years) joined this study. An ergoFet dynamometer was used to determine foot muscle strength (Doming, T1, T23 and T2345), and ankle muscle strength (plantarflexion and dorsiflexion). The morphology of FIMs and extrinsic foot muscle was determined using a Doppler ultrasound system, whereas the postural stability was assessed through Limits of Stability test. Independent samples t-test was used to determine the differences in strength and morphological parameters and Spearman correlation analysis was used to determine whether an association existed between muscle strength and postural stability parameters in the elderly.

Results

Compared with young adults, foot muscle strength and ankle muscle strength (Doming, T1, T23, T2345, dorsiflexion, and plantarflexion, all p <0.05) and the morphology of foot muscles (all p <0.05) were significantly reduced in the elderly. The strength of FIMs and the limit of stability (r = 0.302-0.424, all p <0.05) were significantly correlated in the elderly.

Conclusion

Compared with young adults, the weakness of strength as well as the morphological decline of the intrinsic and extrinsic foot muscles were found in the elderly. In addition, a correlation was observed between FIM's strength and postural stability in the elderly, suggesting their potential role in posture stability.

Association between postoperative fall history and toe grip strength in patients after total knee arthroplasty: A prospective observational study

BACKGROUND

Factors associated with falls after total knee arthroplasty (TKA) have been rarely reported. The aim of this study was to identify factors that influence the incidence of falls after TKA, focusing on toe grip strength (TGS) in particular, which has been associated with falls in older adults.

METHODS

217 patients who underwent TKA were included and followed up for 1 year. Main study outcome measures were the presence or absence of falls within 1 year after TKA. Multiple logistic regression analysis was used with postoperative falls as the dependent variable and preoperative falls and postoperative TGS on the affected sides as independent variables.

RESULTS

170 (43 and 127 in the fall and non-fall groups) patients were included in the analysis. The presence of a preoperative falls history before TKA and a weak postoperative affected TGS indicated an increased susceptibility of the patient to fall postoperatively.

CONCLUSIONS

Results of the current study revealed the association between postoperative TGS and postoperative falls. We highlight the importance of preoperative fall monitoring and postoperative TGS evaluation to prevent falls after TKA.

Reliability of enhanced paper grip test for testing foot strength in volleyball and soccer players

OBJECTIVES

To evaluate the reliability of the Enhanced Paper Grip Test (EPGT) for assessing foot strength in volleyball and soccer players.

DESIGN

A cross-sectional observational study with repeated measurements.

SETTING

Field-based study.

PARTICIPANTS

A convenience sample of 28 athletes (13 volleyball players and 15 soccer players) participated in the study.

MAIN OUTCOME MEASURES

The main outcome measures were the intraclass correlation coefficients (ICC) for intra-visit and inter-visit reliability, typical error, and coefficient of variation for the force (N) recorded in EPGT test.

RESULTS

The EPGT demonstrated good to excellent relative reliability (ICC values ranged from 0.93 to 0.97) and acceptable absolute reliability (typical error = 5-8 % of the mean). Significant inter-limb asymmetries were observed in both volleyball (16.0 ± 10.2%) and soccer players (15.3 ± 9.8%).

CONCLUSIONS

The EPGT is a reliable tool for assessing foot strength in volleyball and soccer players. Further research is required to explore the applicability of EPGT in different athletic and clinical contexts, and its potential role in athletic performance and injury prevention.

Effect of Exercises for Strengthening the Intrinsic Muscles of the Foot and Improving Ankle Mobility on Patients of Diabetic Peripheral Neuropathy

Background and objectives The study aimed to compare the efficacy of standard home care versus structured ankle mobility exercises in enhancing ankle and foot joint range of motion (ROM) among individuals with diabetes mellitus (DM). Additionally, it investigated the impact of foot intrinsic muscle strengthening exercises on hallux grip force in those with Diabetic Peripheral Neuropathy (DN). Materials and methods In a study of 200 patients with Diabetic Neuropathy (DN), selected from 345 screened diabetics with stable glucose levels and routine monitoring at a tertiary care facility, the efficacy of structured exercises versus standard care was evaluated. Participants, aged 40-70 years with mild neuropathic symptoms (neuropathy disability score of 3 to 5), were divided into two groups. Group 1 received standard care per International Diabetic Foot guidelines, while Group 2 performed targeted foot intrinsic muscle strengthening and ankle mobility exercises over eight weeks. The range of motion (ROM) for ankle and first metatarsophalangeal (MTP) joints and hallux grip force were measured, showing significant improvements in Group 2. Analysis was done using IBM SPSS. Results The average age of the individuals in group 1 (n=100) was 53.87±5.42 years, whereas the average age of the subjects in group 2 (n=100) was 54.23±4.69 years. The study included a total of 97 male participants, with 48 in group 1 and 49 in group 2. The groups exhibited homogeneity in terms of age, gender, duration of DM, and BMI (p>,0.05). When comparing the ROM for ankle dorsiflexion between the groups, it was shown that subjects in group 2 had a substantially higher ROM following exercise for both the right (27.97°±5.3° Vs 19.24°±2.54°) and left (28.55°±4.61° Vs 18.22°±1.14°) ankles compared to the patients in group 1 (p<,0.01). Nevertheless, there were statistically insignificant differences (p>,0.05) observed within the groups, both before and after the exercises, for all the variables examined except for right and left ankle dorsiflexion, and right ankle plantarflexion in group 2. Group 2 subjects exhibited a considerably greater hallux grip force compared to group 1 subjects. The mean enhanced paper grip strength for the right and left big toe of group 2 was 44±3.58 N and 43.2±2.62 N respectively. The mean enhanced paper grip force for the right and left big toe of group 1 was 38±3.11 N and 37.92±2.13 N respectively. A statistically highly significant difference was observed for hallux grip force between the groups (p<,0.01). Conclusion The findings of this study suggest that performing the foot intrinsic muscle strengthening and ankle mobility exercises on the foot and ankle joints can potentially enhance ROM and hallux grip force in patient groups with DN.

The enhanced paper grip test can substantially improve community screening for the risk of falling

BACKGROUND

Lower-limb strength measures can enhance falls risk assessment but due to the lack of clinically applicable methods, such measures are not included in current screening. The enhanced paper grip test (EPGT) is a simple-to-use and cost-effective test that could fill this gap. However, its outcome measure (EPGT force) has not yet been directly linked to the risk of falling.

RESEARCH QUESTION

Is the EPGT a good candidate for falls risk screening in older people in the community?

METHODS

Seventy-one older people living independently in the community were recruited for this prospective observational study (median age 69 y, range 65y-79y). Lower-limb and whole-body strength were assessed at baseline using the EPGT and a standardised hand-grip method respectively. Incident falls were recorded monthly for a year through follow-up telephone conversations. The capacity of individual strength measures to predict falls and to enhance an established falls risk assessment tool (FRAT) commonly used by UK's national health service (NHS) was assessed using binomial logistic regression. The analysis was repeated for the subset of participants without history of falling at baseline (prediction of first-ever falls).

RESULTS

Increased EPGT force and increased symmetry in strength between limbs were significantly associated with reduced risk of falling. Compared to the NHS-FRAT, the EPGT correctly classified more people (73% vs 69%), it achieved higher sensitivity (56% vs 26%) and higher negative predictive value (76% vs 68%). Complementing the NHS-FRAT with the EPGT produced a more comprehensive model that correctly classified 91% of participants and achieved 98% specificity, 81% sensitivity, 89% negative and 96% positive predictive value. Replacing the EPGT with hand-grip strength consistently undermined prediction accuracy. The EPGT remained highly accurate when focused on the prediction of first-ever falls.

SIGNIFICANCE

The EPGT can substantially enhance falls screening in the community. These results can also inform effective personalised strength exercise interventions.

Reliability and clinical applicability of lower limp strength using an enhanced paper grip strength

The enhanced paper grip test (EGPT) quantitatively assesses lower limb strength. EGPT assesses the hallux grip force by reacting a pulling force derived from a card, being positioned underneath the participant's hallux. This study aimed to investigate the repeatability and clinical applicability of the EPGT for assessing foot muscle strength. EPGT force was measured using a dynamometer. The reliability of the measurement of EPGT force was assessed by having two examiners performing the test on the same group of healthy adults. Clinical applicability was assessed in community-dwelling adults of both genders. EPGT force was recorded for both feet using the same standardised protocol for all participants. Regarding reliability, 20 healthy adults aged 23.04±5.5 years participated in the present study. The EGPT demonstrated good to excellent test-retest (ICC1,2 0.8 to 0.86) and interrater reliability (ICC1,2 0.82 to 0.88). A convenience sample of 15 community-dwelling adults (71.6±7.8 years, 68.5% women) was recruited for clinical applicability testing. All participants performed the test with mean score 15±5.7 N. EPGT is a reliable measurement of the hallux grip force strength and can be used for clinical and research purposes.

The impact of diabetic polyneuropathy on toe grip strength in patients with type 2 diabetes mellitus: a cross-sectional study

Purpose

Type 2 diabetes mellitus (T2DM) and concomitant diabetic polyneuropathy (DPN) induce muscle weakness. Muscle weakness in the foot is associated with foot deformities and falls. However, factors affecting toe grip strength (TGS) are not well known. Therefore, the present study investigated factors related to TGS in patients with T2DM.

Methods

This was a cross-sectional study involving 100 patients with T2DM who were hospitalized for the treatment of T2DM and 50 healthy adults. The subjects were divided into three groups: a group of healthy subjects, a group of T2DM patients without DPN, and a group of T2DM patients with DPN. Hierarchical multiple regression analysis was performed with TGS and the TGS-to-weight ratio (TGS/Wt%) as dependent variables and with age, the presence of T2DM, and DPN as independent variables, and sex and BMI as confounders.

Results

There were no significant differences in age or sex among the three groups. In the final regression analysis, age and presence of T2DM and DPN were associated in both models with TGS and TGS/Wt% as dependent variables.

Conclusion

DPN, T2DM, and age were found to be related to TGS. The findings of this study could contribute to healthcare providers developing foot care and rehabilitation programs for diabetic patients.

Trial registration

This study was registered with UMIN-CTR (UMIN000034320) on 1 November 2018.

An exploration of the mechanistic link between the enhanced paper grip test and the risk of falling

The enhanced paper grip test (EPGT) offers an easy-to-use measure of hallux plantar-flexion strength that does not need expensive specialised equipment. Literature suggests that it could be a useful screening tool to assess the risk of falling in older people. However, research on a specific mechanistic link to the risk of falling is lacking. It is hypothesised here that muscle weakening (assessed by the EPGT) is indicative of impaired ability to recover balance after a slip or a trip. To get an initial assessment of validity of the above hypothesis, the EPGT is compared against an established lab-based measure of lower-limb strength that is capable of assessing a person's ability to recover balance after a slip or a trip: maximum isometric leg press push-off force (leg press force). A gender-balanced sample of twenty people (median age=34 y) was recruited. Two different but equaly valid techniques of administering the EPGT were included regarding whether the participants' ankle was supported by the examiner or not. Results for the two EPGT techniques differed susbtantialy but they were both significantly associated with leg press force and therefore linked to better ability to maintain balance after a slip or a trip. The "ankle not held" EPGT technique was more strongly correlated to leg press force (r(18) = 0.652, p = 0.002) than the "ankle held" (r(18) = 0.623, p = 0.003) and appears to be the more favourable technique to administer the EPGT. These findings offer new insight on a potential mechanistic link between the EPGT and the risk of falling and support its optimal use in future research involving older people.

A Novel Intrinsic Foot Muscle Strength Dynamometer Demonstrates Moderate-To-Excellent Reliability and Validity

Background

Intrinsic foot muscle (IFM) weakness can result in reduced foot function, making it crucial for clinicians to track IFM strength changes accurately. However, assessing IFM strength can be challenging for clinicians, as there is no clinically applicable direct measure of IFM strength that has been shown to be reliable and valid with the foot on the ground.

Purpose

The purpose was to investigate the intra-rater and inter-rater reliability of a novel, budget-friendly IFM dynamometer and determine its agreement with a handheld dynamometer (HHD). The researchers also examined correlations of foot morphology and activity level to IFM strength.

Study design

Descriptive Laboratory Study.

Methods

Two assessors measured IFM strength of 34 healthy volunteers (4 male, 30 female; age=21.14±2.57, height=164.66 ±7.62 cm, mass=64.45±11.93 kg) on two occasions 6.62±0.78 days apart with the novel dynamometer to assess intra- and inter-rater reliability. The HHD was used to measure IFM in the first session in order to assess validity.

Results

For the novel dynamometer, intra- and inter-rater reliability was moderate-to-excellent (ICC = 0.73 - 0.95), and the majority of the strength tests were within the 95% limits of agreement with the HHD. Wider foot morphology and a higher number of days walking over the prior seven days had small but significant correlations with IFM strength (dominant foot r = 0.34, non-dominant foot r = 0.39; r = -0.33, -0.39 respectively).

Conclusion

This novel IFM dynamometer is a budget-friendly ($75) tool that was shown to be reliable and valid in a healthy population.

Levels of evidence

Level 3©The Author(s).

Development and Earliest Validation of a Portable Device for Quantification of Hallux Extension Strength (QuHalEx)

Hallux strength is associated with sports performance and balance across the lifespan, and independently predicts falls in older adults. In rehabilitation, Medical Research Council (MRC) Manual Muscle Testing (MMT) is the clinical standard for hallux strength assessment, but subtle weakness and longitudinal changes in strength may go undetected. To address the need for research-grade yet clinically feasible options, we designed a new load cell device and testing protocol to Quantify Hallux Extension strength (QuHalEx). We aim to describe the device, protocol and initial validation. In benchtop testing, we used eight precision weights to apply known loads from 9.81 to 78.5 N. In healthy adults, we performed three maximal isometric tests for hallux extension and flexion on the right and left sides. We calculated the Intraclass Correlation Coefficient (ICC) with 95% confidence interval and descriptively compared our isometric force-time output to published parameters. QuHalEx benchtop absolute error ranged from 0.02 to 0.41 (mean 0.14) N. Benchtop and human intrasession output was repeatable (ICC 0.90-1.00, p < 0.001). Hallux strength in our sample (n = 38, age 33.5 ± 9.6 years, 53% female, 55% white) ranged from 23.1 to 82.0 N peak extension force and 32.0 to 142.4 N peak flexion, and differences of ~10 N (15%) between toes of the same MRC grade (5) suggest that QuHalEx is able to detect subtle weakness and interlimb asymmetries that are missed by MMT. Our results support ongoing QuHalEx validation and device refinement with a longer-term goal of widespread clinical and research application.

Plantar intrinsic foot muscle activation during functional exercises compared to isolated foot exercises in younger adults

BACKGROUND

Training the plantar intrinsic foot muscles (PIFMs) has the potential to benefit patients with lower extremity musculoskeletal conditions as well as the aged population. Isolated foot exercises, often standard in clinical practice, are difficult to perform, whereas functional exercises are much easier to accomplish. However, it is unclear whether functional exercises are comparable to isolated foot exercises in activating the PIFMs.

OBJECTIVE

This study aims to compare the activation of PIFMs between functional exercises versus isolated foot exercises.

METHODS

Using surface electromyography (EMG), muscle activation of three PIFMs was measured in four functional exercises (i.e. normal/unstable toe stance, toe walking, and hopping) versus a muscle-specific isolated foot exercise in 29 younger adults, resulting in 12 comparisons.

RESULTS

Functional exercises showed larger mean EMG amplitudes than the isolated foot exercises in 25% of the 12 comparisons, while there was no difference in the remaining 75%.

CONCLUSION

Functional exercises provoked comparable or even more activation of the PIFMs than isolated foot exercises. Given that functional exercises are easier to perform, this finding indicates the need to further investigate the effectiveness of functional exercises in physical therapy to improve muscle function and functional task performance in populations that suffer from PIFM weakness or dysfunction.

Intrinsic muscles of the foot: Anatomy, function, rehabilitation

The intrinsic muscles of the foot are underappreciated structures in evaluating and treating lower extremity dysfunction. These muscles play a crucial role in the proper function of the foot during sport activities. The functions of these muscles are not generally well understood. Intrinsic dysfunction can lead to a variety of problems. Therefore, it is important for clinicians to have a good understanding of the anatomy and function of the intrinsic foot muscles in order to properly diagnose and treat foot injuries in patients. Published research on the rehabilitation of the intrinsic muscles provides insight into the function as well as benefits of treatment. The purpose of this review is to summarize the published research on the anatomy, function, contribution to pathology, as well as rehabilitation options for the intrinsic muscles of the foot.

Relationship between fall history and toe grip strength in older adults with knee osteoarthritis in Japan: A cross-sectional study

BACKGROUND

Knee osteoarthritis (KOA), one of the most common musculoskeletal diseases in older adults, is associated with a high incidence of falls. Similarly, toe grip strength (TGS) is associated with a history of falls in older adults; however, the relationship between TGS and falls in older adults with KOA who are at risk of falling is not known. Therefore, this study aimed to determine if TGS is associated with a history of falls in older adults with KOA.

METHODS

The study participants, older adults with KOA scheduled to undergo unilateral total knee arthroplasty (TKA), were divided into two groups: non-fall (n = 256) and fall groups (n = 74). Descriptive data, fall-related assessments, modified Fall Efficacy Scale (mFES), radiographic data, pain, and physical function including TGS were evaluated. The assessment was conducted on the day before performing TKA. Mann-Whitney and chi-squared tests were performed to compare the two groups. Multiple logistic regression analysis was performed to determine the association of each outcome with the presence or absence of falls.

RESULTS

Mann-Whitney U test revealed that the fall group had statistically significantly lower height, TGS on the affected and unaffected sides, and mFES. Multiple logistic regression analysis revealed that the incidence of fall history is associated with TGS on the affected side; the weaker the affected TGS of the KOA, the more likely the individual is to fall.

CONCLUSIONS

Our results indicate that TGS on the affected side is related to a history of falls in older adults with KOA. The significance of evaluating TGS among patients with KOA in routine clinical practice was demonstrated.

Morphological and Mechanical Properties of Lower-Limb Muscles in Type 2 Diabetes: New Potential Imaging Indicators for Monitoring the Progress of DPN

The aim of this study was to explore changes in morphological and mechanical properties of lower-limb skeletal muscles in patients with diabetes with and without diabetic peripheral neuropathy (DPN) and seek to find a potential image indicator for monitoring the progress of DPN in patients with type 2 diabetes mellitus (T2DM). A total of 203 patients with T2DM, with and without DPN, were included in this study. Ultrasonography and ultrasound shear wave imaging (USWI) of the abductor hallux (AbH), tibialis anterior (TA), and peroneal longus (PER) muscles were performed for each subject, and the shear wave velocity (SWV) and cross-sectional area (CSA) of each AbH, TA, and PER were measured. The clinical factors influencing AbH_CSA and AbH_SWV were analyzed, and the risk factors for DPN complications were investigated. AbH_CSA and AbH_SWV in the T2DM group with DPN decreased significantly (P < 0.05), but no significant differences were found in the SWV and CSA of the TA and PER between the two groups. Toronto Clinical Scoring System (CSS) score and glycosylated hemoglobin (HbA1c) were independent predictors of AbH_CSA and AbH_SWV. As AbH_SWV and AbH_CSA decreased, Toronto CSS score and HbA1c increased and incidence of DPN increased significantly. In conclusion, the AbH muscle of T2DM patients with DPN became smaller and softer, while its morphological and mechanical properties were associated with the clinical indicators related to the progression of DPN. Thus, they could be potential imaging indicators for monitoring the progress of DPN in T2DM patients.

Effects of Insole with Toe-Grip Bar on Barefoot Balance and Walking Function in Patients with Parkinson's Disease: A Randomized Controlled Trial

The maintenance and improvement of balance and walking function in patients with Parkinson’s disease (PD) is essential. Toe dysfunction in patients with PD is related to balance and walking. Recently, insoles have been developed to improve toe function, but their effects on the physical functions of patients with PD remain unclear. In this randomized controlled study, we investigated the effects of insoles with a toe-grip bar on balance and walking function in such patients. Twenty-nine patients with PD in Hoehn and Yahr stages II−IV were randomly assigned to an intervention or control group. Patients in the intervention and control groups wore shoes having insoles with and without a toe-grip bar for 4 weeks, respectively. The center of gravity sway of standing posture (total trajectory length, envelope area, and maximum anterior−posterior center of pressure [AP-COP] distance) and walking parameters at normal and fast speeds were measured pre- and post-intervention in the rehabilitation room. All measurements were performed with the participants being barefoot. The maximum AP-COP distance and step length of the fast-walking condition were significantly improved in the intervention compared to the control group (p < 0.05). Thus, insoles with a toe-grip bar may improve balance and walking function in patients with PD.

Individual Cofactors and Multisensory Contributions to the Postural Sway of Adults with Diabetes

To assess the interactions between individual cofactors and multisensory inputs on the postural sway of adults with type 2 diabetes and healthy subjects, 69 adults accepted to participate in the study (48 with/ 21 without diabetes). Assessments included neuro-otology (sinusoidal-rotation and unilateral-centrifugation), ophthalmology and physiatry evaluations, body mass index (BMI), physical activity, quadriceps strength, the ankle/brachial index and polypharmacy. Postural sway was recorded on hard/soft surface, either with eyes open/closed, or without/with 30° neck extension. The proportional differences from the baseline of each condition were analyzed using Multivariate and Multivariable analyses. Patients with polyneuropathy and no retinopathy showed visual dependence, while those with polyneuropathy and retinopathy showed adaptation. Across sensory challenges, the vestibulo-ocular gain at 1.28 Hz and the BMI were mainly related to changes in sway area, while the dynamic visual vertical was mainly related to changes in sway length. The ankle/brachial index was related to the effect of neck extension, with contributions from quadriceps strength/physical activity, polyneuropathy and polypharmacy. Across conditions, men showed less sway than women did. In conclusion, in adults with diabetes, sensory inputs and individual cofactors differently contribute to postural stability according to context. Rehabilitation programs for adults with diabetes may require an individualized approach.

A Prediction Model for Falls in Community-Dwelling Older Adults in Podiatry Practices

INTRODUCTION

Falls are a worldwide health problem among community-dwelling older adults. Emerging evidence suggests that foot problems increase the risk of falling, so the podiatrist may be crucial in detecting foot-related fall risk. However, there is no screening tool available which can be used in podiatry practice. The predictive value of existing tools is limited, and the implementation is poor. The development of risk models for specific clinical populations might increase the prediction accuracy and implementation. Therefore, the aim of this study was to develop and internally validate an easily applicable clinical prediction model (CPM) that can be used in podiatry practice to predict falls in community-dwelling older adults with foot (-related) problems.

METHODS

This was a prospective study including community-dwelling older adults (≥65 years) visiting podiatry practices. General fall-risk variables, and foot-related and function-related variables were considered as predictors for the occurrence of falls during the 12-month follow-up. Logistic regression analysis was used for model building, and internal validation was done by bootstrap resampling.

RESULTS

407 participants were analyzed; the event rate was 33.4%. The final model included fall history in the previous year, unsteady while standing and walking, plantarflexor strength of the lesser toes, and gait speed. The area under the receiver operating characteristic curve was 0.71 (95% CI: 0.66-0.76) in the sample and estimated as 0.65 after shrinkage.

CONCLUSION

A CPM based on fall history in the previous year, feeling unsteady while standing and walking, decreased plantarflexor strength of the lesser toes, and reduced gait speed has acceptable accuracy to predict falls in our sample of podiatry community-dwelling older adults and is easily applicable in this setting. The accuracy of the model in clinical practice should be demonstrated through external validation of the model in a next study.

Forefoot Injuries in Athletes: Integration of the Movement System

Despite the prevalence of forefoot related problems in athletes, there are few comprehensive summaries on examination and intervention strategies for those with forefoot related symptoms. While many factors may contribute to pathology and injury, the presence of abnormal foot alignment can negatively affect lower extremity biomechanics and be associated with injuries. Physical therapists may use the characteristics associated abnormal pronation or abnormal supination to describe the movement system disorder and serve as a guide for evaluating and managing athletes with forefoot pathologies. Athletes with an abnormal pronation movement system diagnosis typically demonstrate foot hypermobility, have decreased strength of the tibialis posterior muscle, and present with a medially rotated lower extremity position. Athletes with abnormal supination movement system diagnosis typically demonstrate foot hypomobility, decreased strength of the fibularis muscles, and a laterally rotated lower extremity position. Interventions of manual therapy, taping, strengthening exercises, and neuromuscular reeducation can be directed at the identified impairments and abnormal movements. The purpose of this clinical commentary is to integrate a movement system approach in pathoanatomical, evaluation, and intervention considerations for athletes with common forefoot pathologies, including stress fractures, metatarsalgia, neuroma, turf toe, and sesamoiditis. By applying a prioritized, objective problem list and movement system diagnosis, emphasis is shifted from a pathoanatomical diagnosis-based treatment plan to a more impairment and movement focused treatment.

LEVEL OF EVIDENCE

5.

The Association between Chronic Hemodialysis and Toe Pinch Force in Japanese Patients: Cross-Sectional Study

The purpose of this cross-sectional study was to investigate the effect of chronic hemodialysis on toe pinch force (TPF). A total of 37 chronic hemodialysis patients without type 2 diabetes mellitus (T2DM) (age: 69.4 ± 11.8 years, duration of hemodialysis: 3.5 ± 3.4 years) were enrolled in this study. The TPF in chronic hemodialysis patients without T2DM was compared with that in 34 apparently healthy participants and 37 chronic hemodialysis patients with T2DM. There was no significant difference in clinical profiles between healthy participants and chronic hemodialysis patients with and without T2DM. The TPF in chronic hemodialysis patients without T2DM was lower compared with that in healthy participants (2.70 ± 1.05 kg vs. 3.34 ± 0.99 kg, p = 0.025). In addition, the TPF in patients with T2DM was even lower compared with that in patients without T2DM (2.12 ± 1.01 kg vs. 2.70 ± 1.05 kg, p = 0.042). This study showed a dramatic reduction in TPF in chronic hemodialysis patients, especially in those with T2DM.

Toe Support Pattern as a New Predictive Factor Associated with Falls in Older People with Psychiatric Disorders

BACKGROUND

Maintaining autonomy is one of the principal objectives for seniors and people with psychiatric disorders. Podiatric medical care can help them maintain autonomy. This work aimed to characterize and quantify the support of the toes in a psychiatric population by analyzing the influence of psychotropic medications and toe and foot support parameters on the prevalence of falls.

METHODS

We conducted a cross-sectional descriptive study in 67 participants (31 people with psychiatric disorders and 36 without diagnosed disorders [control population]). Toe support pattern was analyzed with a pressure platform. Variables were measured in static and dynamic loading and related to falls and psychotropic medication use.

RESULTS

The psychiatric population fell more than the control population and presented less toe-ground contact in static measurements, although it has more foot-ground contact time. Maximum toe pressure during toe-off is also less intensive in the psychiatric population and is related to people who take psychotropic medications.

CONCLUSIONS

Toe support pattern could be used as a predictive factor for falls and to improve stability in these populations.

Effects of age and locomotor demand on foot mechanics during walking

Older adults exhibit reductions in push-off power that are often attributed to deficits in plantarflexor force-generating capacity. However, growing evidence suggests that the foot may also contribute to push-off power during walking. Thus, age-related changes in foot structure and function may contribute to altered foot mechanics and ultimately reduced push-off power. The purpose of this paper was to quantify age-related differences in foot mechanical work during walking across a range of speeds and at a single fixed speed with varied demands for push-off power. 9 young and 10 older adults walked at 1.0, 1.2, and 1.4 m/s, and at 1.2 m/s with an aiding or impeding horizontal pulling force equal to 5% BW. We calculated foot work in Visual3D using a unified deformable foot model, accounting for contributions of structures distal to the hindfoot's center-of-mass. Older adults walked while performing less positive foot work and more negative net foot work (p < 0.05). Further, we found that the effect of age on mechanical work performed by the foot and the ankle-foot complex increased with increased locomotor demand (p < 0.05). Our findings suggest that during walking, age-related differences in foot mechanics may contribute to reduced push-off intensity via greater energy loss from distal foot structures, particularly during walking tasks with a greater demand for foot power generation. These findings are the first step in understanding the role of the foot in push-off power deficits in older adults and may serve as a roadmap for developing future low-cost mobility interventions.

A new simpler approach to measure the strength of toe plantar flexion requiring no mechanical restraint with a light-weight device

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.

Relationship between lower limb muscle strength and hallux valgus severity in older people

OBJECTIVE

To examine differences in lower limb muscle strength between older people with varying degrees of hallux valgus deformity.

METHODS

Muscle strength was measured at the knee, ankle and foot using hand-held dynamometry and a clinical test of toe strength (the paper grip test) in 157 older people (99 women and 58 men) aged 65 to 91 (mean 74.1, SD 5.9) years. Hallux valgus severity was documented as none, mild, moderate or severe using validated photographs. Differences in muscle strength according to hallux valgus severity were evaluated using analysis of variance, adjusting for age. Paper grip test performance was compared across the hallux valgus severity groups using the chi-square (χ²) statistic.

RESULTS

Knee extension, ankle joint dorsiflexion, ankle joint plantar flexion, ankle joint inversion, ankle joint eversion and lesser toe plantarflexion strength were not significantly different across the four hallux valgus severity groups. However, there was a significant, dose-response reduction in hallux plantarflexion strength with increasing severity of hallux valgus. This persisted after adjustment for age (F₃ = 5.5, p = 0.001) with a medium effect size (partial η² = 0.10). The number of participants who could successfully complete the paper grip test of the hallux significantly reduced across the four hallux valgus categories (χ² = 18.5, p < 0.001).

CONCLUSIONS

There is a specific and progressive reduction in hallux plantarflexion strength with increasing severity of hallux valgus in older people. This finding has potential implications for both the aetiology and treatment of this common and disabling condition.

Intrinsic foot muscle strengthening exercises with electromyographic biofeedback achieve increased toe flexor strength in older adults: A pilot randomized controlled trial

BACKGROUND

Toe flexor strength is important for preventing older adults from falling. Although intrinsic foot muscles are the main determinants of toe flexor strength, exercises for strengthening these muscles are difficult for older adults. This study therefore aimed to determine whether the use of electromyographic biofeedback helps older adults to perform intrinsic foot muscle strengthening exercises.

METHODS

This randomized controlled trial had two parallel arms. Participants were randomly allocated to the control group or the electromyographic biofeedback group. Control participants performed two progressive intrinsic foot muscle strengthening exercises twice a week for 6 weeks. Participants in the other group performed these exercises assisted by electromyographic biofeedback. Primary outcome measures were changes in toe flexor strength and the timed up-and-go and functional reach tests (the latter two being balance tests).

FINDINGS

Altogether, 23 older adults were randomized to the control group (n = 12) or the electromyographic biofeedback group (n = 11). After the 6-week intervention, toe flexor strength on the dominant side increased in both groups (P < 0.017). However, toe flexor strength on the nondominant side increased only in the electromyographic biofeedback group (P < 0.017), with a large effect size of 1.5. There were no changes in the two balance tests. Three of the control group and two of the electromyographic biofeedback group were lost to follow- up.

INTERPRETATION

Our results indicate that, the use of electromyographic biofeedback can enhance the effect of intrinsic foot muscle strengthening exercises on the nondominant side in older adults.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000036521.

Reliability and validity of an enhanced paper grip test; A simple clinical test for assessing lower limb strength

BACKGROUND

The paper-grip-test (PGT) involves pulling a small card from underneath the participant's foot while asking them to grip with their hallux. The PGT is shown to be effective in detecting foot muscle-weakening but its outcome is operator-dependent. To overcome this limitation, an enhanced PGT (EPGT) is proposed that replaces the pass/fail outcome of the PGT with a continuous measurement of the pulling force that is needed to remove the card (EPGT-force).

RESEARCH QUESTION

Is the EPGT-force an accurate, reliable and clinically applicable measurement of strength?

METHODS

Reliability and clinical applicability were examined in two ways. Firstly, two examiners measured EPGT-force for twenty healthy volunteers in a test/retest set-up. EPGT force was measured using a dynamometer, the hallux grip force was measured using a pressure mat. The clinical applicability of the EPGT was tested in ten people with diabetes. Postural sway was also measured.

RESULTS

Interclass correlation coefficients (ICC) revealed excellent inter-rater reliability (ICC > 0.75). Intra-rater reliability was excellent for the first examiner (ICC = 0.795) and good for the second (ICC = 0.703). Linear regression analysis indicated that hallux grip force accounted (on average) for 83 %±4 % of the variability in EPGT force. This strong relationship between EPGT force and hallux grip force remained when the test was performed in a clinical setting with the latter accounting for 88 % in EPGT force variability. Spearman rank order correlation showed that people with diabetes with a higher difference in EPGT force between limbs swayed more.

SIGNIFICANCE

EPGT force is a reliable and accurate measurement of hallux grip force. Hallux grip force was previously found to be strongly correlated to the strength of all muscle groups of the foot and ankle and to the ability to maintain balance. The proposed EPGT could be used to monitor muscle weakness in clinics for better falls-risk assessment.

One-Year Outcome Study of Anatomic Reconstruction of Lesser Metatarsophalangeal Joints

Background: Lesser metatarsophalangeal joint (MTPJ) and plantar plate pathologies are commonly seen forefoot conditions. Traditional rebalancing techniques are commonly used but can have concerning adverse effects. The purpose of this study was to analyze the 1-year outcomes of a new technique consisting of anatomic repair of the plantar plate and collateral ligaments involving lesser MTPJs. Methodology: A retrospective cohort study of 50 consecutive patients treated with anatomic plantar plate and collateral ligament reconstruction were evaluated for lesser MTPJ imbalances between 2013 and 2016. The primary outcome was postoperative digital stability defined as a normal dorsal drawer test and normal paper pull-out test. Secondary outcomes included pre- and postoperative visual analogue scale pain measurements, MTPJ radiographic alignment, and ACFAS Forefoot module scores. Results: All patients had digital instability prior to the surgical intervention. Final follow-up revealed that 92% of patients showed improved digital stability, P = .0005. Multivariate regression found statistically significant improvement in pain reduction via the visual analogue scale of 51.2 mm (P < .0001) and ACFAS Forefoot module scores improved to 92 (P < .0001). The 45 joints with preoperative abnormal transverse plane deformity, had either complete (n = 29) or partial (n = 16) radiographic MTPJ correction. Conclusion: These results suggest that anatomic repair of lesser MTPJ improved digital stability, pain, function and radiographic alignment with greater than one year of follow-up.Levels of Evidence: Level IV: Retrospective cohort study.

Effects of Long-Term Use of Insoles with a Toe-Grip Bar on the Balance, Walking, and Running of Preschool Children: A Randomized Controlled Trial

This randomized controlled study is aimed at investigating the effects of long-term use of insoles with a toe-grip bar on the balance, walking, and running of preschool children. Fifty-two preschool children were randomly assigned to an intervention group or control group. Children included in the intervention group wore shoes with insoles that had a toe-grip bar, and those in the control group wore shoes with regular insoles without a toe-grip bar for 4 weeks while they were at school. The center of gravity sway (total trajectory length and envelope area), walking parameters (walking speed, cadence, stride length, step length, stance time, and swing time), and time to run 25 m were measured before and after the intervention. The 25 m running time of the intervention group was significantly improved after the intervention (F = 5.66; p < 0.05). This study suggests that insoles with a toe-grip bar may contribute to improvements in the running of preschool children.

Functional assessments of foot strength: a comparative and repeatability study

Background

Evaluating the strength of the small muscles of the foot may be useful in a variety of clinical applications but is challenging from a methodology standpoint. Previous efforts have focused primarily on the functional movement of toe flexion, but clear methodology guidelines are lacking. A novel foot doming test has also been proposed, but not fully evaluated. The purposes of the present study were to assess the repeatability and comparability of several functional foot strength assessment techniques.

Methods

Forty healthy volunteers were evaluated across two testing days, with a two-week doming motion practice period between them. Seven different measurements were taken using a custom toe flexion dynamometer (seated), custom doming dynamometer (standing), and a pressure mat (standing). Measurements from the doming dynamometer were evaluated for reliability (ICCs) and a learning effect (paired t-tests), while measurements from the toe flexion dynamometer and pressure mat were evaluated for reliability and comparability (correlations). Electromyography was also used to descriptively assess the extent of muscle isolation in all measurements.

Results

Doming showed excellent within-session reliability (ICCs > 0.944), but a clear learning effect was present, with strength (p < 0.001) and muscle activity increasing between sessions. Both intrinsic and extrinsic muscles were engaged during this test. All toe flexion tests also showed excellent reliability (ICCs > 0.945). Seated toe flexion tests using the dynamometer were moderately correlated to standing toe flexion tests on a pressure mat (r > 0.54); however, there were some differences in muscle activity. The former may better isolate the toe flexors, while the latter appeared to be more functional for many pathologies. On the pressure mat, reciprocal motion appeared to display slightly greater forces and reliability than isolated toe flexion.

Conclusions

This study further refines potential methodology for foot strength testing. These devices and protocols can be duplicated in the clinic to evaluate and monitor rehabilitation progress in clinical populations associated with foot muscle weakness.

Effect of foot care interventions for older adults using day care services

AIM

This study explored the prevalence of foot problems among older adults and the effectiveness of foot care interventions for improving toe-gap force and foot flexibility. Foot problems are very common among people aged 65 years and older. However, the effects of foot care interventions on components underlying these issues (i.e., toe-gap force and foot flexibility) are unclear.

DESIGN

This was a quasi-experimental study.

METHODS

Eighteen older adults were divided into three groups: medical foot care intervention, combined intervention and control group. The combined intervention group received medical foot care, foot hygiene and five-toed socks. Toe-gap force and foot flexibility were measured.

RESULTS

The most common foot problems were hallux valgus, toe deformities, nail discoloration and thickness and dryness. Significant differences in right foot toe-gap force were observed between the combined intervention and control groups. There were no significant differences in foot flexibility between groups.

The relationship between hallux grip force and balance in people with diabetes

BACKGROUND

Diabetes accelerates the decline in muscle strength in older people and substantially increases the risk for fall and injury. Weakening of lower extremity muscles, in particular, is a strong predictor for falls, but currently there is no established method for its assessment in clinics. The paper grip test (PGT) offers a qualitative assessment of hallux plantar flexor strength and its usefulness for predicting falls has been demonstrated in non-diabetic populations.

RESEARCH QUESTION

The aim of this study is to test whether the PGT can be used for a quantitative assessment of lower-extremity strength and to investigate its relationship with isometric muscle strength and balance in people with diabetes and peripheral neuropathy.

METHODS

Isometric muscle strength of all muscle groups of the foot-ankle was assessed using a dynamometer in sixty-nine people with diabetes and neuropathy. Postural sway and the gripping force exerted by the participants during the PGT was measured for the same participants using a plantar pressure assessment system. These measurements were repeated in regular intervals for 18 months in a longitudinal observational cohort study.

RESULTS

Cross-sectional analysis of baseline data showed that people who failed the PGT swayed more. Analysis of longitudinal data showed that increasing hallux grip force is significantly associated with reduced postural sway. No significant association was found between dynamometry-based measurements of strength and postural sway. Hallux grip force was significantly correlated to the strength of all muscle groups of the foot-ankle complex.

SIGNIFICANCE

These results indicate that hallux grip force can assess the strength of the foot-ankle muscles and could potentially be used to identify people at risk of falling. This sets the basis for the development of new screening protocols to assess weakening of the muscles of the foot-ankle and to enhance risk assessment for falls in people with diabetes and peripheral neuropathy.

Hallux plantar flexor strength in people with diabetic neuropathy: Validation of a simple clinical test

AIM

To validate the paper grip test for assessing plantar flexion strength of the hallux.

METHODS

Plantar flexor strength for 69 people with diabetic neuropathy was assessed: (a) using the paper grip test while simultaneously a plantar pressure platform quantified the force under the hallux, and (b) using a hand-held dynamometer. Following testing, participants were divided into groups: (1) passed vs. failed paper grip test (2) males vs. females. Statistical analyses determined if differences were evident between the groups and assessed the relationship between the paper grip test and the hand-held dynamometer. The discrimination ability, sensitivity, specificity, and reproducibility of the paper grip test was established.

RESULTS

Participants who passed the paper grip test demonstrated greater grip force at the hallux than those who failed, and they also exhibited greater isometric maximum force during the hand-held dynamometry test (p ≤ 0.05). Grip force for males was significantly higher than for females. A moderate positive correlation between the paper grip test and the hand-held dynamometer was evident.

CONCLUSIONS

In the population examined the paper grip test was found to be a valid clinical tool; it offers a non-invasive, inexpensive, and quick method to assess plantar flexion strength of the hallux.

Utricular hypofunction in patients with type 2 diabetes mellitus

The aim of this study was to assess the function of the utricle and horizontal semicircular canals in patients with type 2 diabetes mellitus receiving primary health care, with/without a history of falls. 101 patients with type 2 diabetes mellitus, 34 to 84 years old (26 with and 75 without a history of falls) and 51 healthy volunteers (40-83 years old) accepted to participate. They denied having a history of dizziness, vertigo, unsteadiness, hearing loss, or neurological disorders. None of them were seeking care due to sensory or balance decline. After a clinical evaluation and report of symptoms related to balance using a standardised questionnaire, lateral canal function was assessed by sinusoidal rotation at 0.16 Hz and 1.28 Hz (60°/sec peak velocity), otolith function was assessed by static visual vertical (average of 10 trials) and dynamic visual vertical during unilateral centrifugation (300°/sec at 3.5 cm) and static posturography was performed on hard/ soft surface with eyes open/closed. Compared to healthy volunteers, patients showed decreased responses to unilateral centrifugation, but similar responses to horizontal canal stimuli (independently of age, peripheral neuropathy or a history of falls) (ANCoVA p < 0.05) and a larger sway area with a lengthier sway path. Compared to patients with no falls, patients with falls had a higher female/male ratio and a higher frequency of score ≥ 4 on the questionnaire of symptoms related to balance, but similar age, body mass index and frequency of peripheral neuropathy. In patients with type 2 diabetes mellitus, receiving primary healthcare who are not seeking care due to sensory or balance decline, utricular function may be impaired even in the absence of horizontal canal dysfunction or a history of falls.

Within and between-days repeatability and variability of plantar pressure measurement during walking in children, adults and older adults

BACKGROUND

Previous studies discussed the repeatability and variability in plantar pressure measurement, but a few considered different age groups. Here we determine within and between-days repeatability and variability of plantar pressure measurement during gait in participants from different age groups.

METHOD

Plantar pressure was recorded in children, young adults and older adults walking at preferred speed in four non-consecutive days within one week. Data from 10 steps from each foot in each day were analyzed considering the different regions of the foot. Mean and peak plantar pressure and data variability were compared between the steps, foot regions and days.

RESULTS

To describe mean and peak pressure during gait in children and adults a single measurement can be enough, but elderly will requires more attention especially concerning peak values. Variability in mean pressure did not differ between age groups, but peak pressure variability differed across foot regions and age groups.

CONCLUSION

One single observation can be used to describe plantar pressure during gait in children and adults. When the interest concerns older people, it might be pertinent to consider more than one day of assessment, especially when looking at peak pressure.

Effect of Insoles with a Toe-Grip Bar on Toe Function and Standing Balance in Healthy Young Women: A Randomized Controlled Trial

Objective

The aim of this randomized controlled study was to investigate the effects of insoles with a toe-grip bar on toe function and standing balance in healthy young women.

Methods

Thirty female subjects were randomly assigned to an intervention group or a control group. The intervention group wore shoes with insoles with a toe-grip bar. The control group wore shoes with general insoles. Both groups wore the shoes for 4 weeks, 5 times per week, 9 hours per day. Toe-grip strength, toe flexibility, static balance (total trajectory length and envelope area of the center of pressure), and dynamic balance (functional reach test) were measured before and after the intervention.

Results

Significant interactions were observed for toe-grip strength and toe flexibility (F = 12.53, p < 0.01; F = 5.84, p < 0.05, resp.), with significant improvement in the intervention group compared with that in the control group. Post hoc comparisons revealed that both groups showed significant improvement in toe-grip strength (p < 0.01 and p < 0.05, resp.), with higher benefits observed for the intervention group (p < 0.01). Conversely, no significant interaction was observed in the total trajectory length, envelope area, and functional reach test.

Conclusions

This study suggests that insoles with a toe-grip bar contribute to improvements in toe-grip strength and toe flexibility in healthy young women.

Reliability of doming and toe flexion testing to quantify foot muscle strength

Background

Quantifying the strength of the intrinsic foot muscles has been a challenge for clinicians and researchers. The reliable measurement of this strength is important in order to assess weakness, which may contribute to a variety of functional issues in the foot and lower leg, including plantar fasciitis and hallux valgus. This study reports 3 novel methods for measuring foot strength – doming (previously unmeasured), hallux flexion, and flexion of the lesser toes.

Methods

Twenty-one healthy volunteers performed the strength tests during two testing sessions which occurred one to five days apart. Each participant performed each series of strength tests (doming, hallux flexion, and lesser toe flexion) four times during the first testing session (twice with each of two raters) and two times during the second testing session (once with each rater). Intra-class correlation coefficients were calculated to test for reliability for the following comparisons: between raters during the same testing session on the same day (inter-rater, intra-day, intra-session), between raters on different days (inter-rater, inter-day, inter-session), between days for the same rater (intra-rater, inter-day, inter-session), and between sessions on the same day by the same rater (intra-rater, intra-day, inter-session).

Results

ICCs showed good to excellent reliability for all tests between days, raters, and sessions. Average doming strength was 99.96 ± 47.04 N. Average hallux flexion strength was 65.66 ± 24.5 N. Average lateral toe flexion was 50.96 ± 22.54 N.

Conclusions

These simple tests using relatively low cost equipment can be used for research or clinical purposes. If repeated testing will be conducted on the same participant, it is suggested that the same researcher or clinician perform the testing each time for optimal reliability.

Associations between ankle dorsiflexion range of motion and foot and ankle strength in young adults

[Purpose] This study assessed the relationships between the ankle dorsiflexion range of motion and foot and ankle strength. [Subjects and Methods] Twenty-nine healthy (young adults) volunteers participated in this study. Each participant completed tests for ankle dorsiflexion range of motion, hallux flexor strength, and ankle plantar and dorsiflexor strength. [Results] The results showed (1) a moderate correlation between ankle dorsiflexor strength and dorsiflexion range of motion and (2) a moderate correlation between ankle dorsiflexor strength and first toe flexor muscle strength. Ankle dorsiflexor strength is the main contributor ankle dorsiflexion range of motion to and first toe flexor muscle strength. [Conclusion] Ankle dorsiflexion range of motion can play an important role in determining ankle dorsiflexor strength in young adults.

Efficacy of a progressive resistance exercise program to increase toe flexor strength in older people

BACKGROUND

Reduced toe flexor strength is an independent predictor of falls in older people. However it is unknown whether strengthening programs can restore toe flexor strength in older individuals. The aim of this study was to investigate whether a progressive resistance training program, focused specifically on the foot muscles, could improve toe flexor strength in community-dwelling older people.

METHODS

After baseline testing, 85 men and women (age range 60-90years) were randomized to either a supervised, progressive resistance training (n=43) or a home-based exercise (n=42) group for 12weeks. A further 32 participants were recruited for a control group. The primary outcome measures were hallux and lesser toe flexor strength pre- and post-intervention. Secondary outcome measures were exercise compliance, components of the Foot Health Status Questionnaire and single-leg balance time.

FINDINGS

Average class attendance was 89% with 68 participants from the two intervention groups (80%) completing the follow-up assessments. Participants in the supervised, progressive resistance training group significantly increased their toe strength (up to 36%; P<0.02), whereas there was no change in toe strength in either the home-based or control groups. This increased toe strength was accompanied by a significant improvement in perceived general foot health and single-leg balance time compared to the other groups (P<0.05).

INTERPRETATION

Progressive resistance exercises are a viable intervention to increase toe flexor strength in older adults. A clinical trial is now required to determine whether this intervention can reduce the number of falls suffered by older adults.

Effects of Age on Strength and Morphology of Toe Flexor Muscles

Study Design Descriptive, cross-sectional. Background Age-related muscle atrophy is common in lower-limb muscles. We therefore speculated that foot muscles may also diminish with age. However, there is a paucity of literature characterizing foot muscle strength and morphology, and any relationship between these 2, in older people. Objective To compare the strength and size of the toe flexor muscles of older adults relative to their younger counterparts. Methods Seventeen young adults with a normal foot type were matched by sex and body mass index to 17 older adults with a normal foot type, from an available sample of 41 younger (18 to 50 years of age) and 44 older (60 or more years of age) adults. Among the matched groups (n = 34), muscle thickness and cross-sectional area for 5 intrinsic and 2 extrinsic toe flexor muscles were obtained using ultrasound. Toe strength was assessed using a pressure platform. Differences in toe flexor strength and muscle size between the young and older matched groups were determined using analysis of covariance (controlling for height). Correlations between strength and size of the toe flexor muscles of the pooled group (n = 34) were also calculated. Results Toe strength and the thickness and cross-sectional area of most foot muscles were significantly reduced in the older adults (P<.05). Hallux and toe flexor strength values were strongly correlated with the size of the intrinsic toe flexor muscles. Conclusion The smaller foot muscles appear to be affected by sarcopenia in older adults. This could contribute to reduced toe flexion force production and may affect the ability of older people to walk safely. Interventions aimed at reversing foot muscle atrophy in older people require further investigation. J Orthop Sports Phys Ther 2016;46(12):1065-1070. Epub 29 Oct 2016. doi:10.2519/jospt.2016.6597.

Relationship of toe pinch force to other muscle strength parameters in men with type 2 diabetes

OBJECTIVE

The aim of this study was to explore the relations between toe pinch force and other muscle strength parameters in male patients with type 2 diabetes mellitus.

METHODS

A total of 40 men with type 2 diabetes (age: 53.4 ± 13.1 years, duration of diabetes: 8.5 ± 8.1 years) who needed exercise training were enrolled in this cross-sectional study. We evaluated the clinical parameters and 4 muscle strength parameters, which were toe pinch force, handgrip strength, isometric knee extension force, and isometric ankle dorsiflexion force.

RESULTS

The HbA1c, toe pinch force, handgrip strength, isometric knee extension force, and isometric ankle dorsiflexion force were 10.1 ± 2.4 %, 3.2 ± 1.2 kg, 37.3 ± 7.0 kg, 39.6 ± 11.4 kgf, and 17.0 ± 6.3 kgf, respectively. Toe pinch force was significantly correlated with handgrip strength (r = 0.365, p = 0.0206), isometric knee extension force (r = 0.668, p < 0.0001), and isometric ankle dorsiflexion force (r = 0.514, p = 0.0007). All muscle strength parameters were significantly lower in patients with diabetic polyneuropathy than in those without polyneuropathy.

CONCLUSION

Although toe pinch force was significantly correlated with the other muscle strength parameters, the correlation was not so strong. However, evaluation of toe pinch force might be recommended for assessment of distal limb muscle strength in patients with type 2 diabetes.

Pathogenesis of Fifth Metatarsal Fractures in College Soccer Players

Background:

The pathogenesis of fifth metatarsal stress fractures remains uncertain.

Hypothesis:

Physical characteristics and environmental factors, which have received limited attention in the literature thus far, might be involved in the development of fifth metatarsal stress fractures.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

To test the study hypothesis, a medical examination and survey of the living environment of collegiate soccer players was conducted and correlated with the existence of fifth metatarsal stress fractures. The survey and measurements were conducted in 273 male athletes from the same college soccer team between 2005 and 2013. A medical examination comprising assessment of stature, body weight, body mass index, foot–arch height ratio, toe-grip strength, quadriceps angle, leg-heel angle, functional reach test, single-leg standing time with eyes closed, straight-leg raise angle, finger-floor distance, heel-buttock distance, ankle joint range of motion, and a general joint laxity test were performed once a year, along with a questionnaire survey. The survey was also repeated when a fifth metatarsal stress fracture was diagnosed. The study participants were separated into a fifth metatarsal stress fracture injury group and a noninjury group. The measurement items and survey items were compared, and the association between the factors and the presence or absence of injuries was analyzed.

Results:

Toe-grip strength was significantly weaker in the injury group compared with the noninjury group, suggesting that weak toe-grip is associated with fifth metatarsal stress fracture (P < .05). In addition, fifth metatarsal stress fractures were more common in the nondominant leg (P < .05). Between-group comparisons of the other items showed no statistically significant differences.

Conclusion:

The association between weak toe-grip strength and fifth metatarsal fracture suggests that weak toe-grip may lead to an increase in the load applied onto the lateral side of the foot, resulting in stress fracture. The finding of stress fracture being more common in the nondominant leg needs further study.

Intra-rater reliability of hallux flexor strength measures using the Nintendo Wii Balance Board

Background

The purpose of this study was to investigate the intra-rater reliability of a new method in combination with the Nintendo Wii Balance Board (NWBB) to measure the strength of hallux flexor muscle.

Methods

Thirty healthy individuals (age: 34.9 ± 12.9 years, height: 170.4 ± 10.5 cm, weight: 69.3 ± 15.3 kg, female = 15) participated. Repeated testing was completed within 7 days. Participants performed strength testing in sitting using a wooden platform in combination with the NWBB. This new method was set up to selectively recruit an intrinsic muscle of the foot, specifically the flexor hallucis brevis muscle. Statistical analysis was performed using intra-class coefficients and ordinary least product analysis. To estimate measurement error, standard error of measurement (SEM), minimal detectable change (MDC) and percentage error were calculated.

Results

Results indicate excellent intra-rater reliability (ICC = 0.982, CI = 0.96-0.99) with an absence of systematic bias. SEM, MDC and percentage error value were 0.5, 1.4 and 12 % respectively.

Conclusions

This study demonstrates that a new method in combination with the NWBB application is reliable to measure hallux flexor strength and has potential to be used for future research and clinical application.

Effectiveness of foot and ankle exercise programs on reducing the risk of falling in older adults: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Foot and ankle (FA) exercise programs might reduce the risk of falling in older adults. We sought to systematically review the current literature on FA exercise programs targeted at reducing the risk of falling in older adults.

METHODS

A systematic literature search was performed in the PubMed database, the Physiotherapy Evidence Database, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Central Register of Controlled Trials. Articles were included based on the following criteria: 1) randomized controlled trial, 2) FA exercise program, and 3) use of fall risk-related motor outcomes (strength, balance, flexibility, and functional ability) or use of falls as an outcome. Weighted effect sizes (d) were calculated across studies for estimating the overall effect of FA exercises on the most frequently reported motor outcome parameters.

RESULTS

Eight publications met the inclusion criteria. Small to moderate overall effects were found for balance (d = 0.46, P < .001) and ankle flexibility (d = 0.29, P = .006). No significant overall effects were found for ankle plantarflexor strength (d = 0.11, P = .223) and walking performance (d = -0.05, P = .404). Controversial results were reported for other functional measures. Effects varied depending on the type of intervention. Only one study reported improved ankle evertor strength and a significant reduction in falls.

CONCLUSIONS

Evidence suggests that FA exercise can improve certain fall risk-related motor outcomes and reduce falls. Limited effects on strength and functional ability might be related to insufficient training intensity and lack of adherence. Further studies that include progressive strength and flexibility training are necessary to validate which FA exercise programs are most effective at preventing falls.

Association between toe flexor strength and spatiotemporal gait parameters in community-dwelling older people

Background

The toe flexor muscles perform a crucial function to control foot movement and assist with propulsive force when walking. However, the association between toe flexor strength and spatio-temporal gait parameters is largely unknown. Spatiotemporal gait parameters represent gait characteristics, and are good measures of the functional status and degree of safe ambulation among community-dwelling older adults. Herein, we examined the association between the toe flexor strength and spatiotemporal gait parameters in community-dwelling older adults.

Methods

Ninety-three community-dwelling older people (mean age: 73.2 ± 4.2 years, 53 women) participated in this study. The strength of the toe flexor muscles was assessed using a toe strength measuring instrument and a strain gauge. The measurements were performed once on each foot, and the average of the right and left was used in the analysis. Gait analysis was performed on a 15-m walkway under usual- and fast-pace conditions. The medial 10-m walking time was measured and walking speed was calculated. Acceleration and angular velocity of the right heel were measured using a wireless miniature sensor unit and used to compute cadence, percent of swing time in gait cycle (%swing time), and stride length.

Results

In multiple regression analyses adjusted for age, sex, body height, body weight, and hand grip strength, no associations between toe flexor strength and spatiotemporal gait parameters at usual pace were found. Conversely, under the fast-pace condition, decreased toe flexor strength was significantly associated with slower walking speed (β = 0.22, p = 0.049), lower%swing time (β = 0.34, p = 0.009), and shorter stride length (β = 0.22, p = 0.011) after adjustment.

Conclusion

In community-dwelling older people, decreased strength of toe flexor was correlated with slower walking speed, shorter periods of single-limb support phase, and shorter stride length during fast-pace walking. These data provide further support for an important role of toe flexor muscles in walking.

Electronic supplementary material

The online version of this article (doi:10.1186/1743-0003-11-143) contains supplementary material, which is available to authorized users.

Correlates of foot pain severity in adults with hallux valgus: a cross-sectional study

Background

Hallux valgus (HV) is highly prevalent and associated with progressive first metatarsophalangeal joint subluxation and osteoarthritis. The link between structural HV deformity and foot pain is unclear. This study investigated possible explanatory factors surrounding foot pain in HV, including radiographic HV angle and signs of joint degeneration.

Methods

Participants were 60 adults (53 female) with HV aged 20 to 75 years. Participant demographics and a range of radiographic, clinical and functional measures were considered potential correlates of foot pain. Self-reported foot pain (visual analogue scales and a dichotomous definition) was considered the dependent variable. Multivariate modelling was used to determine which characteristics and measures explained pain, with univariate analyses first used to screen potential variables.

Results

Approximately 20 to 30% of the variance in foot pain associated with HV could be explained by patient characteristics such as poorer general health status, lower educational attainment and increased occupational physical activity levels, in combination with some dynamic physical characteristics such as hallux plantarflexion weakness and reduced force-time integral under the second metatarsal during gait. Neither increasing lateral deviation of the hallux (HV angle) nor presence of first metatarsophalangeal joint osteoarthritis was associated with foot pain.

Conclusions

This study shows that passive structural factors, including HV angle, do not appear to be significant correlates of foot pain intensity in HV. Our data demonstrate the importance of considering patient characteristics such as general health and physical activity levels when assessing foot pain associated with HV.

Reference values for toe grip strength among Japanese adults aged 20 to 79 years: a cross-sectional study

Background

No standardised method has been adopted for measuring toe-grip strength (TGS), and no reference values have been established for evaluating it. The present study investigated age-related changes in TGS and the association of TGS with various descriptive characteristics.

Methods

TGS was measured in both feet of 1842 community-dwelling individuals aged 20–79 years using a toe-grip dynamometer. The participants were classified by decade into six age groups: 20–29, 30–39, 40–49, 50–59, 60–69, and 70–79 years. Correlations for TGS between the dominant and non-dominant sides were analysed according to decade and sex using Pearson’s correlation coefficient. The mean TGS and TGS-to-weight ratio (TGS/Wt%) were compared between sexes by each decade and among all decades by sex using two-way analysis of variance with post-hoc tests. To assess relationships between mean TGS and various descriptive characteristics, we determined Pearson’s correlation coefficient by sex and performed a stepwise multiple-regression analysis. Significance was set at 5%.

Results

Correlations for TGS between the dominant and non-dominant sides were significant in all decades by sex, ranging from 0.73 for men in their 70s to 0.91 for women in their 50s. Mean TGS and TGS/Wt% significantly differed between the sexes in all decades and in all decades except the 40s, respectively. In men, the mean TGS and TGS/Wt% significantly decreased with aging after the 50s and 60s, respectively. In women, both the mean TGS and TGS/Wt% significantly decreased between the 40s and 50s and between the 60s and 70s. TGS significantly correlated with age, height, and weight in both sexes. The stepwise multiple-regression analysis revealed TGS was significantly associated with sex, age, height, and weight (adjusted R² = 0.31).

Conclusions

TGS was closely correlated between the dominant and non-dominant sides. TGS and TGS/Wt were significantly reduced with aging after the 50s in men and significantly reduced between the 40s and 50s and between the 60s and 70s in women. Age, sex, height, and weight accounted for only 30.8% of the variance in TGS. Therefore, other factors (e.g. toe flexibility, structural characteristics) should be considered for improving the accuracy of predicting TGS.

Flexion strength of the toes in the normal foot. An evaluation using magnetic resonance imaging

Flexion of the toes may be active from muscle contraction or passive from the reversed windlass function of the plantar aponeurosis. The aim of this study was to estimate the flexion moments the muscles of the foot and long digital flexors may be capable of generating and compare these calculations with published data. Magnetic resonance images were used to measure the maximal cross-sectional area of the foot muscles and long digital flexors, along with the radius of curvature of the metatarsal heads. Using known physiological data the maximal flexion moments the muscles may be able to generate at the metatarsophalangeal (MTP) joints were calculated. The methodology overestimates muscle strength and flexion moments at the metatarsophalangeal joints. The calculated maximal flexion moment at the 1st MTP joint is 4.27-6.84 Nm, for the 2nd, 3rd and 4th MTP joints 3.06-4.91 Nm, and the 5th MTP joint 0.47-0.75 Nm. The flexion moments the muscles may generate at the MTP joints do not account for the flexion forces seen in normal walking. Given that maximal strength is not used in normal walking, we conclude that the reversed windlass mechanism of the plantar aponeurosis must be important in normal function of the toes.

Importance and challenges of measuring intrinsic foot muscle strength

BACKGROUND

Intrinsic foot muscle weakness has been implicated in a range of foot deformities and disorders. However, to establish a relationship between intrinsic muscle weakness and foot pathology, an objective measure of intrinsic muscle strength is needed. The aim of this review was to provide an overview of the anatomy and role of intrinsic foot muscles, implications of intrinsic weakness and evaluate the different methods used to measure intrinsic foot muscle strength.

METHOD

Literature was sourced from database searches of MEDLINE, PubMed, SCOPUS, Cochrane Library, PEDro and CINAHL up to June 2012.

RESULTS

There is no widely accepted method of measuring intrinsic foot muscle strength. Methods to estimate toe flexor muscle strength include the paper grip test, plantar pressure, toe dynamometry, and the intrinsic positive test. Hand-held dynamometry has excellent interrater and intrarater reliability and limits toe curling, which is an action hypothesised to activate extrinsic toe flexor muscles. However, it is unclear whether any method can actually isolate intrinsic muscle strength. Also most methods measure only toe flexor strength and other actions such as toe extension and abduction have not been adequately assessed. Indirect methods to investigate intrinsic muscle structure and performance include CT, ultrasonography, MRI, EMG, and muscle biopsy. Indirect methods often discriminate between intrinsic and extrinsic muscles, but lack the ability to measure muscle force.

CONCLUSIONS

There are many challenges to accurately measure intrinsic muscle strength in isolation. Most studies have measured toe flexor strength as a surrogate measure of intrinsic muscle strength. Hand-held dynamometry appears to be a promising method of estimating intrinsic muscle strength. However, the contribution of extrinsic muscles cannot be excluded from toe flexor strength measurement. Future research should clarify the relative contribution of intrinsic and extrinsic muscles during intrinsic foot muscle strength testing.