Does Consulting an Occupational Medicine Specialist Decrease Time to Return to Work Among Total Knee Arthroplasty Patients? A 12-Month Prospective Multicenter Cohort Study

PURPOSE

The aim of this study is to investigate whether total knee arthroplasty (TKA) patients who consulted an occupational medicine specialist (OMS) within 3 months after surgery, return to work (RTW) earlier than patients who did not consult an OMS.

METHODS

A multi-center prospective cohort study was performed among working TKA patients, aged 18 to 65 years and intending to RTW. Time to RTW was analyzed using Kaplan Meier and Mann Whitney U (MWU), and multiple linear regression analysis was used to adjust for effect modification and confounding.

RESULTS

One hundred and eighty-two (182) patients were included with a median age of 59 years [IQR 54-62], including 95 women (52%). Patients who consulted an OMS were less often self-employed but did not differ on other patient and work-related characteristics. TKA patients who consulted an OMS returned to work later than those who did not (median 78 versus 62 days, MWU p < 0.01). The effect of consulting an OMS on time to RTW was modified by patients' expectations in linear regression analysis (p = 0.05). A median decrease in time of 24 days was found in TKA patients with preoperative high expectations not consulting an OMS (p = 0.03), not in patients with low expectations.

CONCLUSIONS

Consulting an OMS within 3 months after surgery did not result in a decrease in time to RTW in TKA patients. TKA patients with high expectations did RTW earlier without consulting an OMS. Intervention studies on how OMSs can positively influence a timely RTW, incorporating patients' preoperative expectations, are needed.

Constant force muscle stretching induces greater acute deformations and changes in passive mechanical properties compared to constant length stretching

Stretching is applied to lengthen shortened muscles in pathological conditions such as joint contractures. We investigated (i) the acute effects of different types of stretching, i.e. constant length (CL) and constant force (CF) stretching, on acute deformations and changes in passive mechanical properties of medial gastrocnemius muscle (MG) and (ii) the association of acute muscle-tendon deformations or changes in mechanical properties with the impulse or maximal strain of stretching. Forty-eight hindlimbs from 13 male and 12 female Wistar rats (13 weeks old, respectively 424.6 ± 35.5 and 261.8 ± 15.6 g) were divided into six groups (n = 8 each). The MG was initially stretched to a length at which the force was 75%, 95%, or 115% of the force corresponding to estimated maximal dorsiflexion and held at either CF or CL for 30 min. Before and after the stretching protocol, the MG peak force and peak stiffness were assessed by lengthening the passive muscle to the length corresponding to maximal ankle dorsiflexion. Also, the muscle belly length and tendon length were measured. CF stretching affected peak force, peak stiffness, muscle belly length, and tendon length more than CL stretching (p < 0.01). Impulse was associated only with the decrease in peak force, while maximal strain was associated with the decrease in peak force, peak stiffness, and the increase in muscle belly length. We conclude that CF stretching results in greater acute deformations and changes in mechanical properties than CL stretching, which appears to be dependent predominantly on the differences in imposed maximal strain.

Fastball pitching performance only slightly decreases after mobility impediment of the pelvis and trunk-Do (catch-up) compensation strategies come into play?

Background

Baseball pitching performance can be mechanically explained by the summation of speed principle and the principle of optimal coordination of partial momenta. Impeding optimal energy generation or transfer by or between the pelvis and trunk segments could provide valuable insight into possible compensation or catch-up mechanisms that may manifest themselves based on these principles.

Aim

The aim of the present study was to explore the effects of experimentally impeding the mobility of and between the pelvis and trunk segments (1) on ball speed and mechanical peak joint power, and (2) on mechanical peak load of the elbow and shoulder joints at maximal external rotation (MER) during fastball pitching.

Methods

Eleven elite baseball pitchers (mean age 17.4, SD 2.2 years; mean pitching experience 8.9, SD 3.0 years) were instructed to throw at least 15 fastballs as fast and accurately as possible under two conditions. One condition involved impeding the mobility of the pelvis and trunk segments to hamper their ability to rotate independently, which consequently should affect the separation time, defined as the time interval between the pelvis and trunk peak angular velocities. In the other condition, pitchers threw unimpeded. Ball speed, mechanical peak joint power and peak net moment of the elbow and shoulder at MER were compared between conditions using Generalized Estimating Equations (GEE).

Results

In the impeded pitching condition, the mean difference of the separation time was 12.4 milliseconds [95% CI (4.0, 20.7)] and for ball speed 0.6 mph [95% CI (0.2, 0.9)] lower compared to the unimpeded condition. Only the peak pelvic angular velocity, in addition to the trunk, upper arm and forearm, was 45 deg/s [95% CI (24, 66)] higher impeded condition. The mean differences of the joint power and net moments at the shoulder and elbow did not reach statistical significance.

Conclusion

In elite adolescent baseball, the observed pitching performance after experimentally impeding pelvic and trunk mobility undermines a potential distal catch-up strategy based on the summation of speed principle. The increased peak pelvic angular velocity may indicate a compensation strategy following the optimal coordination of partial momenta principle to practically maintain pitching performance.

Cross-Cultural Adaption and Validation of the Dutch Version of the Kerlan-Jobe Orthopaedic Clinic Questionnaire in Juvenile Baseball Pitchers

Monitoring the performance and functional status of baseball pitchers' upper extremity is important in maintaining the athlete's health and performance. This study validated a Dutch translation of the original English Kerlan-Jobe Orthopaedic Clinic (KJOC) against the previously validated Disabilities of the Arm, Shoulder and Hand (DASH) and Western Ontario Shoulder Instability Index (WOSI) questionnaires in a group of talented juvenile Dutch baseball pitchers. Three times, from 2014-2016, 107 pitchers completed the Dutch KJOC, DASH and WOSI questionnaires. Participants' questionnaire scores were analysed for the whole group and the symptomatic player subgroup separately. Internal consistency, construct validity and ceiling and floor effects were examined. Cronbach's alpha was consistently above 0.8 for the three time periods for the whole group, and ranged between 0.62 and 0.86 for the symptomatic subgroup. Spearman's rank correlation coefficients ranged from 0.47 to 0.67 for the whole group and 0.32 to 0.99 for the symptomatic subgroup. No floor effects were observed in the scores of the KJOC and only a ceiling effect for the whole group (15.2%) at one time period. The Dutch version of the KJOC has shown acceptable internal consistency and construct validity and can be used to assess overhead athletes' shoulder and elbow functionality.

Construct validity and reliability of the modified gait efficacy scale for older adults

PURPOSE

To perform a cross-cultural adaptation of the mGES into Dutch and investigate its construct validity, internal consistency, test-retest reliability and floor and ceiling effects in a large cohort of community-dwelling older adults.

MATERIALS AND METHODS

We translated the British version of the mGES into Dutch, back into English, and had a native English speaker review the final version. Next, we included 223 community-dwelling older adults from the 'Veilig in Beweging Blijven' (VIBE) cohort (69.8 [67.6-74.3] years old, 155 (69.5%) female), who filled out both the mGES and the Falls Efficacy Scale-International (FES-I) twice, with a month in between. Construct validity was assessed by Spearman's correlation between the scores on the mGES and the FES-I. Internal consistency was assessed with Cronbach's alpha and test-retest reliability was assessed with the intra class correlation coefficient (ICC(2,1)).

RESULTS

Construct validity (rho = -0.81, p < 0.001), internal consistency (α = 0.95), and test-retest reliability (ICC(2,1)=0.90, 95%CI = [0.87-0.92]) were all excellent. Ceiling effect was observed in 44 (19.7%) participants which suggest caution when evaluating the mGES for fit and confident older adults.

CONCLUSION

The Dutch mGES is a valid and reliable tool to assess confidence in walking and is suggested as a tool for evaluating self-efficacy after interventions aimed at improving gait.IMPLICATIONS FOR REHABILITATIONAssessment and rehabilitation of gait may be affected by self-efficacy of walking performance.We show that the Dutch translation of the modified gait efficacy scale is a valid and reliable tool for assessing self-efficacy of walking.A ceiling effect was observed that was associated with muscle strength and symptoms of depression.The results of the present study underline the use of the modified gait efficacy scale in the assessment and evaluation of self-efficacy of walking in rehabilitation.

Consistency and test-retest reliability of stepping tests designed to measure self-perceived and actual physical stepping ability in older adults

Background

Older adults with an incorrect perception of their physical abilities may fall more often, suggesting a need for tests to quantify self-perceived and actual abilities.

Aims

To determine between-test consistency and test–retest reliability of three tests that measure self-perceived and actual stepping ability in older adults.

Methods

Older adults performed three stepping tests, covering high (bar test) and far steps (river and step tests). We studied between-test consistency in the perceived ability and actual ability of 269 participants at each task and in the difference between these two (degree of misjudgment). We also studied test–retest reliability in 21 participants.

Results

Perceived ability showed moderate consistency (r = 0.46–0.55, p < 0.001) and moderate-to-strong reliability [ICC(2,1) = 0.42–0.63, p < 0.03] for all tests. Actual ability showed strong consistency (r = 0.77, p < 0.001) and strong-to-excellent reliability [ICC(2,1) = 0.68–0.93, p < 0.001]. Degree of misjudgment was weakly consistent between two stepping far tests (r = 0.32, p < 0.001), but not consistent between stepping far and high tests (r = 0.05 and 0.06, p > 0.3). Test–retest reliability of the degree of misjudgment was poor-to-moderate [ICC(2,1) = 0.38 and 0.50, p < 0.05 on the two stepping far tests and ICC(2,1) = − 0.08, p = 0.63 on the stepping high test].

Conclusions

Actual and perceived ability can be consistently and reliably measured across tests, whereas the degree of misjudgment is less reliable and consistent within individuals.

Self-perceived gait stability modulates the effect of daily life gait quality on prospective falls in older adults

BACKGROUND

Quality of gait during daily life activities and perceived gait stability are both independent risk factors for future falls in older adults.

RESEARCH QUESTION

We investigated whether perceived gait stability modulates the association between gait quality and falling in older adults.

METHODS

In this prospective cohort study, we used one-week daily-life trunk acceleration data of 272 adults over 65 years of age. Sample entropy (SE) of the 3D acceleration signals was calculated to quantify daily life gait quality. To quantify perceived gait stability, the level of concern about falling was assessed using the Falls Efficacy Scale international (FES-I) questionnaire and step length, estimated from the accelerometer data. A fall calendar was used to record fall incidence during a six-month follow up period. Logistic regression analyses were performed to study the association between falling and SE, step length or FES-I score, and their interactions.

RESULTS

High (i.e., poor) SE in vertical direction was significantly associated with falling. FES-I scores significantly modulated this association, whereas step length did not. Subgroup analyses based on FES-I scores showed that high SE in the vertical direction was a risk factor for falls only in older adults who had a high (i.e. poor) FES-I score. In conclusion, perceived gait stability modulates the association between gait quality and falls in older adults such that an association between gait quality and falling is only present when perceived gait stability is poor.

SIGNIFICANCE

The results of the present study indicate that the effectiveness of interventions for fall prevention, aimed at improving gait quality, may be affected by a modulating effect of perceived gait stability. Results indicate that interventions to reduce falls in older adults might sort most effectiveness in populations with both a poor physiological and psychological status.

Gel-type autologous chondrocyte implantation for cartilage repair in patients with prior ACL reconstruction: A retrospective two year follow-up

PURPOSE

To describe the early patient-reported outcomes of articular cartilage repair in patients with pain due to grade III or IV articular cartilage defects after prior anterior cruciate ligament (ACL) reconstruction.

METHODS

Nineteen patients underwent a gel-type autologous chondrocyte implantation (GACI) procedure after ACL reconstruction. Median timeframe between ACL reconstruction and GACI procedure was 52 months (range 16 to 369). The average age at chondrocyte implantation was 35 (standard deviation (SD) eight) years and average cumulative articular cartilage defect size was nine (SD four) square centimeter. Outcome was assessed prior to the GACI procedure and two years after GACI using the International Knee Documentation Committee (IKDC) score and the Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Two year post-GACI scores showed a statistically significant improvement of IKDC (13, SD 22, p=.02) and KOOS quality of life (18, SD 27, p=.01) compared to the pre-GACI scores. The other KOOS domains did improve, but not statistically significant. Seven (37%) patients underwent reoperation after the GACI.

CONCLUSION

Patients with prior ACL reconstruction and suffering from ongoing pain associated with cartilage defects can benefit from cartilage repair with GACI.

Are pushing and pulling work-related risk factors for upper extremity symptoms? A systematic review of observational studies

Systematically review observational studies concerning the question whether workers that perform pushing/pulling activities have an increased risk for upper extremity symptoms as compared to workers that perform no pushing/pulling activities. A search in MEDLINE via PubMed and EMBASE was performed with work-related search terms combined with push/pushing/pull/pulling. Studies had to examine exposure to pushing/pulling in relation to upper extremity symptoms. Two authors performed the literature selection and assessment of the risk of bias in the studies independently. A best evidence synthesis was used to draw conclusions in terms of strong, moderate or conflicting/insufficient evidence. The search resulted in 4764 studies. Seven studies were included, with three of them of low risk of bias, in total including 8279 participants. A positive significant relationship with upper extremity symptoms was observed in all four prospective cohort studies with effect sizes varying between 1.5 and 4.9. Two out of the three remaining studies also reported a positive association with upper extremity symptoms. In addition, significant positive associations with neck/shoulder symptoms were found in two prospective cohort studies with effect sizes of 1.5 and 1.6, and with shoulder symptoms in one of two cross-sectional studies with an effect size of 2.1. There is strong evidence that pushing/pulling is related to upper extremity symptoms, specifically for shoulder symptoms. There is insufficient or conflicting evidence that pushing/pulling is related to (combinations of) upper arm, elbow, forearm, wrist or hand symptoms.

Internal consistency, test-retest reliability and concurrent validity of a questionnaire on work-related exposure related to arm, shoulder and neck symptoms in computer workers

The aim of this study was to determine the internal consistency, test-retest reliability and concurrent validity of the RSI QuickScan, a newly developed questionnaire that aims to identify the presumed risk factors for neck, shoulder and arm symptoms in a population of computer workers. The internal consistency was calculated using item analysis. The test-retest reliability and concurrent validity were analysed by calculating the percentage of agreement, Cohen's Kappa and the Ppositive and Pnegative. The concurrent validity was also tested by comparing the results from the new questionnaire with those from the original questionnaires that the current questionnaire was based on, on-site expert observations and direct measurements. The results indicate that the RSI QuickScan is a measurement tool with acceptable internal consistency, reliability and concurrent validity. The questionnaire can be used as a means to rapidly collect data on a large population of office workers and at low cost.

Working height, block mass and one- vs. two-handed block handling: the contribution to low back and shoulder loading during masonry work

The goal of this study was to compare the effects of the task variables block mass, working height and one- vs. two-handed block handling on low back and shoulder loading during masonry work. In a mock-up of a masonry work site, nine masonry workers performed one- and two-handed block-lifting and block-placing tasks at varying heights (ranging from floor to shoulder level) with blocks of varying mass (ranging from 6 to 16 kg). Kinematics and ground reaction forces were measured and used in a 3-D linked segment model to calculate low back and shoulder loading. Increasing lifting height appeared to be the most effective way to reduce low back loading. However, working at shoulder level resulted in relatively high shoulder loading. Therefore, it was recommended to organise masonry work in such a way that blocks are handled with the hands at about iliac crest height as much as possible.

Fatigue effects on tracking performance and muscle activity

It has been suggested that fatigue affects proprioception and consequently movement accuracy, the effects of which may be counteracted by increased muscle activity. To determine the effects of fatigue on tracking performance and muscle activity in the M. extensor carpi radialis (ECR), 11 female participants performed a 2-min tracking task with a computer mouse, before and immediately after a fatiguing wrist extension protocol. Tracking performance was significantly affected by fatigue. Percentage time on target was significantly lower in the first half of the task after the fatigue protocol, but was unaffected in the latter half of the task. Mean distance to target and the standard deviation of the distance to target were both increased after the fatigue protocol. The changed performance was accompanied by higher peak EMG amplitudes in the ECR, whereas the static and the median EMG levels were not affected. The results of this study showed that subjects changed tracking performance when fatigued in order to meet the task instruction to stay on target. Contrary to our expectations, this did not lead to an overall higher muscle activity, but to a selective increase in peak muscle activity levels of the ECR.

Effect of block weight on work demands and physical workload during masonry work

The effect of block weight on work demands and physical workload was determined for masons who laid sandstone building blocks over the course of a full work day. Three groups of five sandstone block masons participated. Each group worked with a different block weight: 11 kg, 14 kg or 16 kg. Productivity and durations of tasks and activities were assessed through real time observations at the work site. Energetic workload was also assessed through monitoring the heart rate and oxygen consumption at the work site. Spinal load of the low back was estimated by calculating the cumulated elastic energy stored in the lumbar spine using durations of activities and previous data on corresponding compression forces. Block weight had no effect on productivity, duration or frequency of tasks and activities, energetic workload or cumulative spinal load. Working with any of the block weights exceeded exposure guidelines for work demands and physical workload. This implies that, regardless of block weight in the range of 11 to 16 kg, mechanical lifting equipment or devices to adjust work height should be implemented to substantially lower the risk of low back injuries.

Pushing and pulling in association with low back and shoulder complaints

AIMS

To examine the association between exposure to pushing/pulling at work and low back and shoulder complaints.

METHODS

A cross sectional questionnaire survey was carried out among 434 workers from several companies with mainly pushing/pulling tasks. From the same companies 188 workers without physically demanding tasks served as reference. The questionnaire was used to assess the exposure to pushing/pulling and other physical risk factors for low back and shoulder complaints. Mean scores at company level were used to classify groups into medium and high exposed to pushing/pulling and a reference group. Psychosocial factors at work were also assessed. Several pain related questionnaires were used to assess the 12 month prevalence of low back and shoulder complaints in three dimensions: trouble (ache, pain, discomfort), pain intensity, and disability. Prevalence rate ratios (PRs) were calculated using Cox's proportional hazards regression analysis.

RESULTS

The 12 month prevalence of low back complaints was almost equal for all three groups. The prevalence of shoulder complaints increased with an increase in exposure level. Adjusted PRs showed that the high exposed group had an increased risk for low back complaints compared to the reference group. For all dimensions of shoulder complaints a clear tendency towards a dose-response relation was observed. The high exposed group had significant PRs for shoulder complaints, ranging from 2.09 to 6.37. Generally, psychosocial factors had a confounding effect for pain intensity and disability, but not for trouble.

CONCLUSIONS

For shoulder complaints a dose-response relation was observed for exposure to pushing/pulling. Low back complaints were less consistently associated with pushing/pulling. Stronger associations were observed for more severe cases of low back and shoulder complaints. It is hypothesised that work related psychosocial factors affect these associations.