Many people have taken to walking, running, and cycling for the benefit of mind and body during the COVID-19 pandemic, and many engage in those activities with others. New, unpublished research coming out of the Netherlands and Belgium suggests that 2 or more people walking, running, or cycling right behind one another should leave much more than 6 ft of space between themselves.
Using animations developed from computational fluid dynamics models, the researchers showed that a cloud of emitted respiratory droplets is entrained in the slipstream–the wake behind any moving person that pushes air slightly behind them–even when he or she exhales normally. People cycling in groups often use the slipstream of the person in front of them to reduce air resistance, but smaller slipstreams also form behind anyone who is walking or running.
Admitting that much more needs to be learned about the coronavirus-infection risk posed by such slipstream-carried droplets, the authors show that when someone walks through the droplet cloud left by the person in front of them, droplets can stick to the following person’s body.
So how far back should you be from the person in front of you when you are out doing these things? The authors recommend the following distances:
- 13 to 16 ft (4 to 5 meters) while walking
- 33 ft (10 meters) when running or cycling slowly
- 65 ft (20 meters) when cycling fast
These preliminary findings suggest that exercising side by side may be safer than exercising one behind another, but doing so is often not practical or safe, especially when cycling on public roads.
Although these data are unpublished, in their white paper the authors said, “We decided it would be unethical to keep the results confidential and keep the public waiting months for the peer review process to be completed.”
OrthoBuzz would like to thank Dr. Freddie Fu, Chair of Orthopaedic Surgery at the University of Pittsburg Medical Center, for bringing this research to our attention.
In 2015, JBJS launched an “article exchange” collaboration with the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) to support multidisciplinary integration, continuity of care, and excellent patient outcomes in orthopaedics and sports medicine.
During the month of June 2018, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “Physical Activity and Exercise Therapy Benefit More Than Just Symptoms and Impairments in People With Hip and Knee Osteoarthritis.”
The authors issue a clear “call to action” for exercise therapy in patients with hip and knee osteoarthritis (OA), not only because it reduces arthritis symptoms, but also because physical activity helps prevent at least 35 chronic conditions and helps treat at least 26 chronic conditions.
In the February 1, 2017 edition of The Journal, Deren et al. provide an important analysis of muscle mass as it relates to mortality in older patients with an acetabular fracture. Among 99 fracture patients studied retrospectively, 42% had sarcopenia, defined in this study as a skeletal muscle index at the L3 vertebral body of <55.4 cm2/m2 for men and <38.5 cm2/m2 for women.
Deren et al. found that low BMI was associated with sarcopenia and that patients with sarcopenia were significantly more likely than patients without sarcopenia to sustain their skeletal injury from a low-energy mechanism. Sarcopenia was also associated with a higher risk of 1-year mortality, especially when in-hospital deaths were excluded. While the authors note that there’s no consensus definition for clinically diagnosing sarcopenia, they conclude that “sarcopenia based on the skeletal muscle index may be a better predictor of mortality than other commonly used classification
There are important subtextual messages in this study for all physicians who manage geriatric patients. Maintenance of muscle mass by resistance exercise (lifting weights, isometrics, etc.) is of critical importance in limiting fall risk and maintaining good balance and bone density. Dietary considerations are intertwined with exercise in maintaining muscle mass among older patients. Resistance training and cardio exercise help to maintain appetite, and adequate protein intake is of utmost importance. When families and medical teams work together, the risk of sarcopenia can be minimized, resulting in lower rates of falls, fewer low-energy fractures, and less mortality.
Marc Swiontkowski, MD
The 3-dimensional spinal deformities associated with scoliosis may affect other organ systems. In the October 5, 2016 issue of The Journal, Shen et al. correlated radiographic severity of thoracic curvature/kyphosis with pulmonary function at rest and exercise capacity measured with a bicycle ergometer. Forty subjects with idiopathic scoliosis were enrolled in the prospective study (mean age 15.5 years), 33 of them female.
The study found no correlation between coronal thoracic curvature and static pulmonary function tests in the female patients. Female patients with a thoracic curve of ≥ 60° had lower blood oxygen saturation at maximal exertion during the exercise test, but overall exercise tolerance did not appear to be correlated with the magnitude of the thoracic curve and kyphosis. According to the authors, taken together, the many specific cardiopulmonary findings in this study suggest that “the cardiovascular system may be less affected than the respiratory system in patients with idiopathic scoliosis.”
Not surprisingly, exercise capacity was better in patients who performed regular aerobic exercise. Although physical training may not be able to change pulmonary pathology in this population, the authors emphasized that physical activity is still recommended for patients with idiopathic scoliosis for maintaining cardiovascular and peripheral muscle conditioning.
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Here is a summary of key findings from Level I and II studies cited in the November 18, 2015 Specialty Update on orthopaedic rehabilitation:
- A prospective comparison of patients who received either skilled physical therapy (PT) or a standardized home exercise program after total knee arthroplasty (TKA) found that range of motion and functional outcome were similar in the two groups after two years, but the home program was nearly half the cost of PT.1
- A randomized trial of 198 patients who underwent TKA compared telerehabilitation with face-to-face rehab. After two months, WOMAC and KOOS scores and functional and range-of-motion tests were all noninferior for telerehabilitation.
- A randomized trial of community-dwelling elderly patients who had undergone hip fracture surgery found that an individualized home-based rehab program produced superior functional outcomes, balance, and mobility recovery when compared with a standard, non-structured home exercise program.2
- A claims-data study of 4733 people who underwent hip or knee replacement found a 29% decrease in postoperative acute service utilization among those who had preoperative PT.
- A randomized trial comparing active transcutaneous nerve stimulation (TENS), placebo TENS, and standard care during rehab for TKA found that adding either active or placebo TENS to standard care significantly reduced movement pain in the immediate postoperative period.3
- A randomized study found that in-hospital sling-based range-of-motion therapy had a clinically beneficial effect up to three months after TKA surgery in terms of passive knee flexion range of motion, compared with an in-hospital continuous passive motion protocol.4
- A randomized trial comparing weight-bearing and non-weight-bearing for nonoperative treatment of Achilles tendon ruptures found no significant between-group differences in the Total Rupture Score or heel-rise strength.
- A systematic review and meta-analysis comprising 402 patients who had undergone surgical Achilles tendon repair found that postoperative early weight-bearing and early ankle motion exercises were associated with a lower minor complication rate and greater functional recovery when compared with conventional immobilization.5
- A randomized trial comparing 12 weeks of individualized resistance training to physiotherapy without resistance training in adolescents and young adults with bilateral spastic cerebral palsy found that neither group demonstrated improvements in performance of daily physical activity.6
- A randomized trial of three methods of weight-bearing training (verbal instruction, bathroom scale training, and haptic biofeedback) found that haptic feedback was superior to the other methods at helping patients maintain weight-bearing status.7
Amputation and Prosthetics
- A systematic review of studies comparing rigid versus soft dressings after amputation determined that rigid dressings resulted in significantly shorter time from amputation to fitting of a prosthesis.8
- A randomized trial of phantom pain found that a protocol of progressive muscle relaxation, mental imagery, and phantom exercises yielded more significant reductions in the rate and intensity of phantom pain than a program of standard physical therapy.9
Low Back Pain
- Among patients with low back pain, a three-way randomized trial (standard care, standard care + extensible lumbosacral orthoses, and standard care + inextensible lumbosacral orthoses) found that inextensible lumbar orthoses led to a greater improvement in Oswestry Disability Index scores than the other two approaches.10
- Büker N,,Akkaya S, Akkaya N, Gökalp O, Kavlak E, Ok N, Kıter AE, Kitiş A.Comparison of effects of supervised physiotherapy and a standardized home program on functional status in patients with total knee arthroplasty: a prospective study. J Phys Ther Sci. 2014 Oct;26(10):1531-6. Epub 2014 Oct 28.
- Salpakoski A, Törmäkangas T, Edgren J, Kallinen M, Sihvonen SE, Pesola M,Vanhatalo J, Arkela M, Rantanen T, Sipilä S. Effects of a multicomponent home-based physical rehabilitation program on mobility recovery after hip fracture: a randomized controlled trial. J Am Med Dir Assoc. 2014 May;15(5):361-8. Epub 2014 Feb 20.
- Rakel BA, Zimmerman MB, Geasland K, Embree J, Clark CR, Noiseux NO,Callaghan JJ, Herr K, Walsh D, Sluka KA. Transcutaneous electrical nerve stimulation for the control of pain during rehabilitation after total knee arthroplasty: A randomized, blinded, placebo-controlled trial. Pain. 2014 Dec;155(12):2599-611.Epub 2014 Sep 28.
- Mau-Moeller A, Behrens M, Finze S, Bruhn S, Bader R, Mittelmeier W. The effect of continuous passive motion and sling exercise training on clinical and functional outcomes following total knee arthroplasty: a randomized active-controlled clinical study. Health Qual Life Outcomes. 2014 May 9;12:68.
- Huang J, Wang C, Ma X, Wang X, Zhang C, Chen L. Rehabilitation regimen after surgical treatment of acute Achilles tendon ruptures: a systematic review with meta-analysis. Am J Sports Med. 2015 Apr;43(4):1008-16. Epub 2014 May 2.
- Bania TA, Dodd KJ, Baker RJ, Graham HK, Taylor NF. The effects of progressive resistance training on daily physical activity in young people with cerebral palsy: a randomised controlled trial. Disabil Rehabil. 2015 Jun 9:1-7. [Epub ahead of print].
- Fu MC, DeLuke L, Buerba RA, Fan RE, Zheng YJ, Leslie MP, Baumgaertner MR, Grauer JN. Haptic biofeedback for improving compliance with lower-extremity partial weight bearing. Orthopedics. 2014 Nov;37(11):e993-8.
- Churilov I, Churilov L, Murphy D. Do rigid dressings reduce the time from amputation to prosthetic fitting? A systematic review and meta-analysis. Ann Vasc Surg. 2014 Oct;28(7):1801-8. Epub 2014 Jun 6.
- Brunelli S, Morone G, Iosa M, Ciotti C, De Giorgi R, Foti C, Traballesi M. Efficacy of progressive muscle relaxation, mental imagery, and phantom exercise training on phantom limb: a randomized controlled trial. Arch Phys Med Rehabil. 2015Feb;96(2):181-7. Epub 2014 Oct 23.
- Morrisette DC, Cholewicki J, Logan S, Seif G, McGowan S. A randomized clinical trial comparing extensible and inextensible lumbosacral orthoses and standard care alone in the management of lower back pain. Spine (Phila Pa 1976). 2014 Oct 1;39(21):1733-42.
In a systematic review of 48 randomized controlled trials, European researchers found that a single type of exercise—either aerobic, resistance, or performance—was more effective for treating knee osteoarthritis than a mix of different exercise types. For pain reduction, quadriceps-specific resistance exercises were the most efficacious. The study, in the March 2014 Arthritis & Rheumatology, also concluded that the best results were achieved when the exercise program was supervised and engaged in thrice weekly for at least four weeks.
A home-based exercise program modestly improved physical function in older adults who completed a standard rehabilitation program after a hip fracture, according to a recent JAMA study.
Half of nearly 200 older adults with limited function after finishing rehab were randomized to home exercises; the other half received in-home and phone-based nutrition education. The exercise group learned functional tasks (such as standing from a chair and climbing a step) during three hour-long home visits by a physical therapist, and then performed the tasks on their own three times weekly for six months. After six months, the exercise group had better scores of physical function — as measured by the Short Physical Performance Battery and Activity Measure for Post-Acute Care — than the control group.
While the clinical importance of these findings remains to be established, the results suggest that an extended period of structured at-home rehabilitation could help older patients sidestep some of the long-term functional limitations that often persist following a hip fracture.