Jar Opening Research Articles

New Aluminum Lug Closure Reduces Removal Torque while Ensuring Hermetic Seals in Glass Jars

The development and introduction of a vacuum release aluminum (VRA) lug closure into the glass jar market constitutes an important innovation in the food packaging industry by significantly reducing the torque needed to remove the lid from the glass jar, thus facilitating jar opening by consumers. The new lids were compared with the industry standard, steel lug closures, for sealing performance and torque removal. Closure of glass jars hot-packed with deionized water was evaluated by measuring pull-up, vacuum, security, and removal torque. The effects of hot-pack temperature from 82 to 93°C and headspace at 6 and 10% on the integrity and opening of glass closures were studied. Jars packed with tomato sauce and capped with both types of lids were evaluated for ease of opening by measuring removal torque. Performance of the new VRA lug lids was similar to that of the standard lids for all parameters measured except removal torque. Removal torque values for jars sealed with VRA lids were 20 to 51% lower than those for the standard lids.

The effect of rheumatoid arthritis on upper extremity functions: A kinematic perspective.

To examine the global upper extremity kinematics in 3D while performing "jar opening motion" in Rheumatoid Arthritis (RA) and to compare these with healthy individuals. Twenty-four women (12 healthy, 12 RA) were included. Evaluations were made with a JAMAR dynamometer, Health Assessment Questionnaire, and 3D kinematic analysis of global upper extremity during "jar opening motion." The time taken during "jar opening motion" was analyzed in 2 parts (Part 1, Part 2), with total time: part 1 + part 2. In addition, shoulder-to-table distance; elbow flexion angle; wrist extension angle; the area scanned and angular rotation by arm, forearm and hand were used in the analysis. Between groups, there was a statistical difference in: bilateral hand grip strength; part 1, part 2, total time; shoulder-to-table distance; elbow flexion angle; the area scanned by hand; angular rotation of arm and hand in favor of the healthy group (P < .05). In stepwise multiple regression analysis, the most predictive variable for disability was elbow flexion, explaining 53.9% of disability. Compared to healthy individuals, individuals with RA have slower motion, more elbow flexion, less hand grip strength, circular pattern in hand, rotation in arm and hand. Increased disability may result in greater load on elbow flexion.

Impact of Silicone Finger Prosthesis in Activities of Daily Living and Passive Function in Proximal Phalanx Index Finger Amputation

The index finger plays a major role in hand function. Subjects who sustain traumatic amputation of the single index finger also suffer both psychological and functional loss. Most of previous studies primarily focused on psychological benefits with finger prosthesis; however, it is essential to identify the functional benefit of the silicone finger in respective activity spectrum. To determine the improvement in function and activities with silicone finger prosthesis in proximal phalanx index finger amputation. Sixteen subjects were evaluated for the grip strength, pinch strength, and activities with dynamometer position II, pinchometer, and DASH questionnaire, respectively. Significant improvement of grip strength revealed in dynamometer position II ( p = 0.041) when tested without and with silicone finger prosthesis. The overall abilities in activities of daily living were improved significantly ( p = 0.005) as assessed by disability of arm, shoulder and hand questionnaire. Large effect sizes were noted in some activities like writing, jar opening, and carrying heavy object. Silicone finger prosthesis provides a functional benefit to the subjects in multiple activities. Partial loss of a finger has a relationship in limitation of hand function. Generally, clinicians prescribe silicone prosthesis for rehabilitation of finger amputee to restore the cosmetic purpose; however, functionality of the finger is also required to be restored. This study describes the role of silicone finger prosthesis on function and different activities for the subjects suffering from the index finger proximal phalanx amputation. Nayak S, Lenka PK, Equebal A, et al. Impact of Silicone Finger Prosthesis in Activities of Daily Living and Passive Function in Proximal Phalanx Index Finger Amputation. Indian J Phys Med Rehab 2019;30(3):59–65.

Reliability and validity of a novel instrument for the quantification of hand forces during a jar opening task

Study DesignClinical Measurement IntroductionJar opening is a task that relies heavily on the ability to generate adequate hand forces and is often reported in the literature as being difficult for women with hand arthritis. Many have studied relationships between diminished grip/pinch strength and occupational performance but few have investigated how much hand force is necessary to successfully engage in manual tasks. Those who studied this have relied on approaches and tools which lack ecology. Additionally, few have instrumented daily objects to understand if joint protection techniques do, in fact, reduce the hand force generation when performing manual tasks. Purpose of the StudyThe objectives of this study were to one) determine the within session repeatability of a device used to quantify these forces and two) probe into the ecological validity of a novel device to be used in the future study of women with hand osteoarthritis to measure hand force requirements and study the impact of joint protection interventions on hand force profiles. MethodsA plastic jar was instrumented with a torque limiter, 6-axis load cell, and six force sensing resistors so as to capture the grip and compressive hand forces which act on a jar lid when opening a sealed jar. To assess intra-rater reliability of the tool and its testing procedures, 31 adult women with hand osteoarthritis were asked untwist the jar's lid so as to break its seal with each hand twice while stabilizing the base with the opposing hand. The agreement between trials of peak forces and torques from each hand was assessed through statistical approaches including Intraclass Correlation Coefficient, Standard Error of the Measurement, and Minimal Detectable Change. The jar's ecological validity was then assessed via survey. ResultsThis instrument and methods yielded good to excellent repeatability across all force outputs. The majority of our subjects (87%) reported the jar to be similar to those used at home, 87% reported to use a similar jar 2-3 times/month or greater, and rated the importance of opening such a jar as being, on average, 8.7/10. DiscussionThe jar instrument appears to have high reliability and ecologic validity. It has the potential to reveal hand force requirements for a population known to have difficulties opening jars and understanding these force thresholds could help to inform therapy goal-setting. Beyond this, it has the potential to support the study of the hand forces used across various joint protection approaches so as to inform best “jar-opening” practices. ConclusionsThis tool was designed to represent the qualities of a standard, large sealed jar while still housing sophisticated kinetic measurement capacities. Our findings support that we have presented a tool which can be used in future study within this population to better understand the hand kinetics associated with the highly problematic task of jar-opening and joint protection strategies intended to reduce hand loads.

Mismatch between jar opening demands and wrist torque strength of consumers in Iran

This study evaluated the potential mismatch between vacuum-sealed jar opening demands and wrist torque strength of 758 (384 males and 374 females) participants aged 5–74 years in Iran. Wrist ulnar/radial (U/R) torque strength of participants and required torque for opening the existing jars (with 2 different sizes – 65 mm and 85 mm diameter lids) were measured using a digital angle torque adaptor and then compared together to identify any potential mismatch between them. The mismatch percentages were defined as the number of participants whose maximal wrist U/R torque strength were lower than the minimum required torque strength for opening the vacuum-sealed jars. Minimum required torque strength for opening the existing 65 mm and 85 mm vacuum-sealed jars were 4.1 Nm and 6.6 Nm, respectively (range = 4.1 Nm to 10.2 Nm). A considerable mismatch (range = 25%–100%) was found between the required torque strength for opening the existing jars and the wrist U/R torque strength of the study population, particularly for females and those aged 5–9 years. A torque limit of 1.8 Nm was proposed for opening jars for the entire population.

Titreşime Maruz Kalan İnşaat İşçileri İçin Optimal Emeklilik Yaşı: Türkiye'de Bir Vaka Çalışması

Vibrations namely; sound waves are the waves that have a certain number of repetitions in a period. The difference from the sound waves is that the sound is transmitted through the air, while the vibration uses the solid parts of the body. Vibrations pass to operators' hands and arms and even to all their bodies from machinery and equipment used in building operations. Vibrations cause many discomforts. Especially in the construction sector, serious health problems are observed in workers working in high-frequency vibration-emitting machines and equipment. The most common of these health problems is a vibratory syndrome, which causes serious occupational and some health problems in the medium and long term. Vibration syndrome sufferers especially in construction works experience functional, social and phycological disabilities. Hence, the insurances and the depreciation of these occupations must be different from those of other employees. In this study, construction workers’ vibration syndrome risk classifications were conducted. Difficulty in tight jar opening, weak hand grip and finger color changes are among the general problems of the employees. According to the questionnaire, finger coldness and finger numbness are less common. According to this results suggestions on necessary precautions and legal legislation were presented. A Taguchi method-based optimization was performed on the retirement age of construction workers exposed to vibration. It is concluded that the working time of construction workers should be re-examined as per the analysis results. Related legislations can be kept up with the date as per the recommended retirement age for each occupation.

Measurement of the Torque Demand for Jar opening and its Relationship with Anthropometric and Physiological Factors

Measurement of the Torque Demand for Jar opening and its Relationship with Anthropometric and Physiological Factors

Determining Validity of Measures of Pain and Perceived Effort of Women With Hand Osteoarthritis During a Jar Opening Task

Determining Validity of Measures of Pain and Perceived Effort of Women With Hand Osteoarthritis During a Jar Opening Task

Differences in the Hand Force Requirements of Women With Hand Arthritis When Opening Jars With and Without Joint Protection Strategies

Abstract Date Presented 4/16/2015 Joint protection for hand osteoarthritis (OA) relies on theory but not empirical evidence. This study focuses on how hand positioning and nonskid materials influence forces, pain, and perceived effort during jar opening. New data challenge the belief that nonskid materials alone reduce hand forces.

A Better Posture Strategy for Fingertip Force and Finger Coordination during a Daily Activity

An effective jar opening movement requires not only the complex integration of the thumb and fingers but also good body segment coordination dependent on the body posture. However, few studies have focused on the effect that jar opening posture has on the finger force integration when the fingertips are grasping the jar in their natural positions, rather than fixed ones, and few have considered the role of the global motor in this task.Forty‐two healthy young subjects participated in this study and performed the jar opening movement using a custom instrument with three opening postures. The results showed that the resultant force and overall torque of the right hand significantly increased from the vertical to the off‐table posture. The thumb produced the greatest resultant, tangential and normal forces when the off‐table posture was used. Further, the average normalized normal forces of the thumb and middle–ring–little finger group were greater for the off‐table posture than those for the vertical posture, whereas no difference was found for the index finger. The normal forces were 3.02–3.36 times greater than the tangential forces for the three finger groups. The thumb had the greatest torque contribution and produced the same torque contributions for all the three postures. The torque contributions of the index finger and the middle–ring–little finger group were 0.56–0.96 times smaller than that of the thumb. This study found a better posture strategy for the young subjects to open a jar with the off‐table posture while sitting, and this was also the best opening posture when comparing the overall torque in this work with that reported in previous studies, no matter whether the subjects were standing or sitting or whatever type of finger group was defined. However, the effect of grasp type and the middle, ring and little fingertip force need to be clarified in future studies. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Comparison of Kinetic Roles of Digits in Two Jar Twisting Directions among Young Females

The jar opening movement requires a complex integration of digits and adequate grasp strength. Unfortunately, many young females have difficulty achieving this task. The opening direction may be an important element related to the force efficiency of hand. However, few studies have been conducted on this topic with an actual human movement. The purpose of this study was to investigate the effect of jar twisting direction on hand kinetics during a maximum voluntary twist. It was hypothesized that changing the twist direction would alter the results of hand kinetics and that an optimal twist direction could be found for opening a jar. Thirty-six healthy young females with mean age, body weight, and height of 23.5 ± 3.6 years, 53.1 ± 6.0 kg, and 160.4 ± 4.3 cm, respectively, were recruited. A custom jar instrument was fabricated to record the kinetics of hand and digit groups. All participants performed jar twisting movements in the clockwise and counterclockwise directions. The results showed that the overall torque and resultant force of right hand increased when a clockwise twist was applied. The resultant force and torque shares of the thumb also increased for the clockwise twist even though those of the middle-ring-little digit group showed no difference and those of the index digit decreased. The index digit and thumb contributed the least and most effort, respectively, for both twisting directions. The thumb was the main force digit. Normal force was the main component of force for all digit groups. The force projections showed that other digit groups not only antagonized the thumb but also one another. The results supported the hypothesis that there were kinetics differences for digits for the two twisting directions. Jar lids could be opened more efficiently in the clockwise direction and kinetics of each digit group also provided as a precursor to jar design modification.

The Effect of Jar Holding Posture on Finger Force and Torque during a Jar-Opening Task for Young Females

Many young females have difficulty opening jars. Although previous studies have attempted to clarify the body posture effect during such a task, the experiments therein focused on a single digit or actions with unnatural finger positions and were further restricted to upper extremity postures. A further study is required to investigate the fingers’ coordination, as well as each subject's natural and self-selected upper extremity posture and finger grasp location when opening a jar. This study focused on the forces and coordination of the right hand fingers during a jar opening movement under both vertical and free-way opening postures. A jar simulator was set up to record the forces applied by finger groups (the thumb, the index–middle finger group, and the ring–little finger group) of the right hand. A self-selected finger position and free-arm posture of each subject were allowed. Results show that the force vectors of the finger groups were all in the counterclockwise direction for both postures. The total force and overall torque of the right hand decreased in the vertical opening posture. The thumb produced greater tangential and resultant forces in the vertical opening posture. Despite normal forces being 1.82–3.54 times the tangential forces for both postures, no difference was found for the normal force to tangential force ratio for each finger group between the two opening postures. The index–middle finger group had similar torque contributions for both postures. The torque contribution of the thumb increased (26% and 21% for vertical and free-way posture, respectively), while the ring–little finger group torque contribution decreased (35% and 42% for vertical and free-way posture, respectively) in the vertical opening posture. As such, the free-way opening posture is the better strategy for young females to open a jar. Copyright © 2013 John Wiley & Sons, Ltd.

Functional Task Kinematics of the Thumb Carpometacarpal Joint

Abnormal biomechanical loading has been identified as an associated risk factor of osteoarthritis in the wrist and hand. Empirical data to date are insufficient to describe the role of altered biomechanics in thumb carpometacarpal (CMC) arthritis. This is a pilot study to evaluate motion analysis of the upper extremity while performing functional tasks. We wished to describe the in vivo kinematics of the thumb and hand in relation to the larger joints of the upper extremity in subjects without arthritis in functional positions at rest and while loading the CMC joint. If reproducible, we then planned to compare kinematics between these subjects and a subject with advanced thumb CMC arthritis. In vivo kinematics of the hand and upper extremity during the functional tasks of grasp, jar opening, and pinch with and without loading of the CMC joint were evaluated using cameras and a motion-capture system in four asymptomatic female subjects and one female subject with advanced radiographic (Eaton Stage IV) osteoarthritis. Kinematics of the hand and upper extremity can be reliably quantified. Loading of the CMC joint did not alter the hand and forearm kinematics in control subjects. In the subject with osteoarthritis, the adduction-extension deformity at the CMC joint resulted in kinematic alterations as compared with the four control subjects. This study represents preliminary steps in defining thumb CMC position, motion, and loading associated with activities of daily living. These findings enhance our understanding of motion at the CMC joint and how it differs in arthritic patients. Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Differences in the Kinematics of Restrained and Unrestrained Conditions of Opening for Two Sizes of Glass Jar

BackgroundOpening glass jars has been noted to be particularly problematic for consumers, leading to many studies related to the opening process. However, most studies place restrictions on jar opening by forcing the jar to remain on the counter or by requiring a specific hand on the closure.ObjectiveThe objectives of this research were (i) to evaluate the effect of restrained and unrestrained conditions on kinematics of jar opening, (ii) to evaluate the effects of jar diameter on kinematics and (iii) to evaluate how user characteristics (e.g. hand size) are associated with kinematics.MethodsKinematic data were collected from 21 participants during two opening conditions using jars with two diameters. Condition 1 restrained the participant by requiring that the jar maintain contact with the counter during the opening procedure. Condition 2 was termed unrestrained and allowed the user to open the jar with no requirements on jar or hand location.ResultsWhen restrained to a counter, the closure hand produced significantly more rotation compared with the closure hand in the unrestrained condition. Differences were not found in the opening motions when comparing jar diameters. However, hand breadth and length were related to the magnitude of rotation of the closure hand.ConclusionsPlacing restrictions on the participant, the orientation or location of the jar aids data analysis but may yield results that are not indicative of the user's actual jar opening process. Impositions on user positioning should be carefully considered in studies investigating the opening process of glass jars. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Mimetic Jar Device Capable of Measuring Dynamic Opening Forces: Development and Validation

INTRODUCTION On a daily basis, individuals open household jars without considering the biomechanical requirements involved, but for some people this task can be difficult to complete. Those with osteoarthritis, fibromyalgia or other neuromuscular conditions need to make accommodations to their hand kinetics to successfully open a jar with minimal pain. Unfortunately, there exists little data to help clinicians suggest proper hand kinetics for these individuals. Many jar instruments have been developed to attempt to address these large populations; however, none of these jar instruments include a combination of : a six-axis load cell capable of measuring the total compensatory forces applied to the jar lid, multiple lid grip sensors, and a torque limiter to repeatedly simulate the experience of opening a sealed jar . Similarly, those who have quantified the forces and moments acting upon a jar have created instruments that are not true to form and presumably alter the natural requirements of the task. Thus, we developed a life-like device to measure the full kinetics of the hand during jar opening, including both grip forces and resultant forces applied to the jar in six degrees of freedom. This instrument was validated by bench top and healthy human subject testing. Subsequent testing with this jar device may help clinicians advise suitable hand kinetics for individuals with neuromuscular conditions to maximize their effective forces on the jar and minimize pain during jar opening. METHODS A jar device was designed and constructed so as to measure the 6-axes of forces and moments applied to the jar between the two hands as well as the grip forces on the lid (Fig. 1). This jar device utilized a torque limiter set to 2.4 Nm and the jar lid would open freely for 45o to provide a similar experience to opening a real jar. The lid was equipped with 5 mm force sensing resistors (FSR) to measure the force magnitude and direction of force application while gripping the lid (Fig. 1B). The instrumentation of the jar was designed to work with two interchangeable lids: 83 mm (Fig. 1A) and 55 mm (Fig. 1C). Each of these jars utilizes the same load cell and torque limiter and a size appropriate instrumented lid with identical force sensing transducers. The large jar is outfitted with 6 sensors equally spaced radially around the lid, while the small jar has 4.

Outcomes in repair of the ulnar collateral ligament of the thumb metacarpophalangeal joint

The ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint (MCPJ) is an important stabilising structure that is frequently injured. A variety of methods have been described to repair the ligament, many of which are used in our unit. A retrospective audit of short-term outcomes was combined with a longer term follow-up study to help identify factors that might influence outcomes and to provide information regarding long-term morbidity which could be used to counsel future patients undergoing UCL repair. Forty-nine patients underwent repair of their UCL over a 5-year period. The commonest complication recorded at an average follow-up of 3.5 months was MCPJ stiffness. A further 11 patients were assessed at an average time of 29 months following surgery. The mean visual analogue scores were 2.5 for stiffness, 2.8 for pain and 2.5 for cold intolerance. Quick-DASH scores averaged 15. The commonest functional problems reported by the patients were in jar opening and in activities requiring a firm grip. Subgroup analysis showed statistically significant differences in tripod and key grip when compared to normal values (p = 0.03, key grip; p = 0.01 tripod grip, paired t test). Buck-Gramcko scores for the thumb were graded as excellent in eight patients and as good in three patients. Repair of the ulnar collateral ligament of the thumb provides a good functional result with few complications with any hand surgeon performing their favoured technique. The patient should be warned of the possibility of long-term weakness in grip when consenting for surgery.

A Novel Instrument for the Quantification of Hand Forces During Jar Opening

The objectives of this study were to: 1) quantify adult hand grip forces exerted on the lid of a sealed jar 2) determine the within session repeatability of a device used to quantify these forces and 3) probe into the ecological validity of this device.

A novel device for evaluating forces during the dynamic jar opening action—Do older and younger adults do things differently?

Package opening tasks have been identified as some of the most challenging that individuals need to perform to access food. There is little previous study of the 3D hand loading that is required to open these products. A novel load measuring device was used to characterise torque, squeeze and compression forces during the dynamic action of jar opening for young and older adults. The current study showed that the older adults used lower squeeze forces (86.1 N vs. 95.4 N) and higher compressive forces (26.9 N vs. 25.2 N) on the jar lid than younger adults. Older adults tended to apply loading to the jar lid slower (0.038 Nm/s vs. 0.044 Nm/s) and to open the jar at a slower rate (0.84 Rad/s vs. 1.59 Rad/s) than young adults whilst using a higher proportion of their maximal grip strength (40% vs. 27%) indicating that older adults used a more cautious opening strategy. These differences suggest that a simple maximal torque test is not sufficient to characterise older adults’ abilities in relation to package opening. The loading required to open packaging should be understood to ensure that packaging design is developed to be inclusive. This is the first report of realistic complex packaging opening loading presented in the literature.

Kinetic analysis of the thumb in jar-opening activity among female adults

Jar opening is commonly viewed as a challenging task for female adults in daily living. The thumb plays a particular role in grasping the jar lid and leading the turning activity through opposition to the other digits. This study measured and compared the force, torque and torque contribution of the thumb in the activity under ordinary grasp patterns and jar-holding positions. A steel jar-like cylinder was custom made to measure the force and torque generated simultaneously by thumb and wrist. Sixteen young females without a history of hand injury were recruited as subjects. The force and torque of the thumb were found to be influenced significantly only by the grasp pattern but its torque contribution was significantly affected only by the jar-holding position. However, overall torque was influenced by both the grasp pattern and the jar-holding position. The torque contribution of the thumb under the four different grasp patterns and jar-holding positions was found to range from 17.4% to 23.9%. The contribution ratios suggest that the thumb may offer a force equivalent to the other digits rather than just a counter force in this activity.

MAGIC-HAND: A bottle and jar opening machine for people with severe disabilities

This paper describes the development of a prototype product named MAGIC-HAND that has been developed to open bottles, jars and packages that require a twisting action. Its intended users are people with severe disabilities, who are not capable of using the current range of package opening tools. MAGIC-HAND is a kitchen accessory device that fits into standard kitchen furniture. The machine uses novel design approaches applying human-centred virtual prototyping methodology. It is highly automated so users need only place the package in the machine, close the door and activate the machine with a single touch of a button. The machine automatically centres the package, grips its base, senses the height of the closure, grips it and twists it open. Safety features are provided to ensure fingers cannot get trapped accidentally. User trials have highlighted both the advantages and disadvantages of the machine. A comparison with current jar and bottle opening machines is provided. Routes to commercialisation are discussed.