!
Effects of Exercise on Osteoporosis In Postmenopausal Women
! ! ! ! ! ! ! ! By: Julia de Castro Grant
Doctoral Candidate University of New Mexico School of Medicine Division of Physical Therapy Class of 2014
! ! ! Advisor: Burke Gurney, PT, PhD, OCS
! !
____________________________________
Signature
Date
! !
__________________
Approved by the Division of Physical Therapy, School of Medicine, University of New Mexico in partial fulfillment of the requirements for the degree of Doctor of Physical Therapy.
Abstract BACKGROUND & PURPOSE Is it possible to slow, halt, or even reverse osteoporosis with exercise? Osteoporosis is a silent disease that has been estimated to affect 10 million individuals in the US. Every year there are millions of cases of osteoporotic fractures. Furthermore, it has been estimated that one in every two Caucasian women will experience an osteoporotic fracture in their lifetime.[C] These fractures represent multiple health complications with impaired quality of life, as well as an economical burden for society.[10] Reviewed research highlights effects of exercise on the progression of osteoporosis on postmenopausal women.
CASE DESCRIPTION This case study considers a 57-year-old postmenopausal female who was prescribed physical therapy for treatment of chronic sciatica and neck pain. Radiographs revealed acute cervical degenerative disease. Past medical history was remarkable for chronic idiopathic osteoporosis. Due to prescription and time limitations, therapy for her osteoporosis was restricted to patient education and a home exercise program.
OUTCOMES Due to time limitations for the intervention proposed to this patient, there were no measurable changes on bone mineral density. However, the clinical question has been answered, and research reviewed in this study provided valuable information on future optimal exercise prescription for patients with similar characteristics.
BOTTOM-LINE High impact activities, combined with resistive training exercise, sustained for a 12 month minimum produce measurable improvements to bone mineral densities in postmenopausal women.
ii
Table of Contents Section 1: Background and Purpose Introduction
1
Section 2: Case Description Medical Diagnosis & History CURRENT LIST OF MEDICATIONS: Systems Review Social & Family History Patient’s Goals for Therapy
Tests & Measurements DXA Table: Comparison Results Functional Limitations Outcome Measures
Evaluation
1 2
2 3 3
3 3 4 4
5
Diagnosis Narrative Assessment Problem List Prognosis Goals Plan of Care Interventions
5 5 5 6 6 7 7
Outcomes
9
PATIENT RELATED INSTRUCTIONS 7
IN CLINIC MANUAL THERAPY AND SUPERVISED EXERCISE PROGRAM: 8
HOME EXERCISE PROGRAM 9
COORDINATION AND COMMUNICATION WITH OTHER HEALTH PROFESSIONALS 9
FAMILY RELATED INSTRUCTIONS 9
Section 3: Review Evidence Based Analysis Implications of Osteoporosis Pharmacological Interventions Diagnosing Osteoporosis: DXA vs. pQCT Research Optimal Exercise Prescription Lean Mass, Exercise, & BMD Body Weight & BMD
11 11 12 13 13 18 19 19 iii
Conclusions
21
Bibliography Appendix A: Article Summaries Adami et al. Bergstrom et al. Engelke et al. Marin et al. Polidoulus et al. Sakai et al. Snow et al. Vainionpää et al.
25 26 27 28 30 31 32 33
Appendix B: Article Worksheets Adami et al., Intervention – Evidence Appraisal Bergstrom et al., Intervention – Evidence Appraisal Engelke et al., Intervention – Evidence Appraisal Marin et al., Prognostic Study – Evidence Appraisal Pollidoulis et al., Systematic Review – Evidence Appraisal Sakai et al., Intervention – Evidence Appraisal Snow et al., Intervention – Evidence Appraisal Vainionpaa et al., Intervention – Evidence Appraisal
35 42 49 57 61 66 73 80
Appendix C: Tables Selection Method of Articles
88
iv
Section 1: Background and Purpose Introduction The aim of this study is to examine the effects of exercise on osteoporosis in postmenopausal women. Osteoporosis is a chronic metabolic bone disease where the body’s breakdown of bone is greater than the formation rate, causing low bone mineral density and increased bone fragility. The progression of osteoporosis is not painful and generally lacks symptoms, making it difficult to diagnose. Some call it a silent disease which makes itself known by a fracture — usually too late in its progression.[12] The clinical question for this case study shall include three parts: •
What are the effects of exercise on osteoporosis?
•
Can exercise slow down the progression of the disease?
•
Can exercise stop, or even reverse, the progression of the disease?
While a strong body of evidence currently supports exercise slowing down the progression of osteoporosis, it is not clear whether it is possible to reverse or curb it altogether. Hence research presented in this study attempts to establish the specific effects of exercise on osteoporosis and identify which type of exercise intervention is most efficient and conducive to long-term management of the disease.
Section 2: Case Description Medical Diagnosis & History The subject patient is a 57-year-old female who was referred to physical therapy with diagnosis of neck pain, and sciatica-like symptoms. According to patient’s primary care doctor, on 10/22/2013, she presented with a complaint of neck pain of two weeks duration with radiation to the left upper extremity, after failed attempts to control pain with chiropractor visits, NSAIDs and TENS unit. Patient was prescribed
1
radiographs, which indicated mild degenerative changes to cervical region on same visit to primary care doctor. Patient described sciatica pain as traveling posteriorly on left leg radiating down to left foot, symptoms were intermittent and pain was sharp. She stated having pursued physical therapy three years ago when her sciatica symptoms started, but having no relief of her pain. Lastly, patient received a couple of cortisone injections, which also proved unsuccessful. The patient has chronic history of idiopathic osteoporosis and is at high risk for fracture. When first diagnosed ten years ago, patient underwent treatment with bisphosphonates. Treatment was discontinued after a few months due to personal reservations to the drug and its side effects. Additionally, past medical history includes left elbow surgery in 1976, partial hysterectomy in 1995, left shoulder surgery in 1996, and appendectomy in 2000. Patient was evaluated at an outpatient physical therapy clinic on 10/23/2013 and received physical therapy twice a week for the last four weeks specifically targeted for neck and sciatica symptoms.
CURRENT LIST OF MEDICATIONS: Hydrocone-Acetominophen 500 mg tablet, orally q 12 hrs Hydrocone-Ibuprofen 200 mg tablet, orally q 12hrs Triamcinolone Acetonide .1% cream, application 2x day Vitamin D 10000 units tablet, orally daily EpiPen .3 mg, injection daily
Systems Review Patient’s cardiovascular, genitourinary, respiratory, gastrointestinal, neurological and integumentary systems all check normal as well as absence of constitutional symptoms (per doctor’s progress note on 11/05/2013).
2
Social & Family History Patient is a missionary, married with no children. She is a landlord, which is her main source of income. She enjoys traveling, and lived in Russia for her missionary work for a decade in the early eighties. She is involved in church activities and is an avid gardener. Recently, she has joined a pyramid business for essential oils that can be used both topically and internally. She has a history of chronic pain and reports suffering from moderate depression. She complains of constant pain, and often feels hopeless about her body ailments. She expresses concern over her osteoporosis, but has not been prescribed physical therapy. She has requested information on exercises for independent management of the disease.
Patient’s Goals for Therapy 1. To decrease sleep disturbances. 2. To strengthen her body. 3. To improve her ability to perform house tasks and yard work. 4. To decrease sciatica and neck pain.
Te s t s & M e a s u r e m e n t s Radiograph results of 10/22/2013 indicate mild disc space narrowing at C4-C5. Vertebral bodies appear intact. Uncal joints spurs cause mild right neural foraminal narrowing at C4-C5.
DXA Table: Comparison Results
!
Hip/Femoral Neck
02/04/11 compared to 10/05/09
11/09/11 compared to 02/04/11
BMD = .538 gm/cm
BMD = .51 gm/cm
Increase since Prior Exam
7.4%
6.3%
T-score
-2.8
-3.1
27% below average
31% below average
2.8 SD
3.1 SD
Bone Mineral Density
Patient Age Group Standard Deviations below age 30 Conclusions
High risk for fracture*
* Based on World Health Organization standards, standard deviation curves and National Osteoporosis Foundation Guide.
3
Lumbar Spine (L2-L4)
02/04/11 compared to 10/05/09
11/09/11 compared to 02/04/11
Bone Mineral Density
BMD = .830
Increase since Prior Exam
3.9%
2.1%
T-score
-2.27
-2.1
14% below average
12% below average
2.27 SD
2.1 SD
Patient Age Group Standard Deviations below age 30 Conclusions
BMD = .85 gm/cm
High risk for fracture*
* Based on World Health Organization standards, standard deviation curves and National Osteoporosis Foundation Guide.
!
Functional Limitations Unable to do laundry, sit for more than one hour, walk for more than 20 minutes, sleep without medication, or do yard work, all secondary to pain.
Outcome Measures Neck Index- 28 or 56% (severe disability) Back Index- 24 or 48% (severe disability) (The maximum score is 50, the higher the number the greater the disability, obtained score can be multiplied by 2 in order to produce a percentage score)
!
Resting vital signs – HR: 70 bpm, PO2 sat: 99%, BP 124/80mmHg Body dimensions - BMI 26.4, height 5’1’’ and weight 140 lbs. Observation – Patient has decreased thoracic kyphosis, forward head posture, forward rounded shoulders, mild bilateral scapular winging and decreased lumbar lordosis. AROM – Measurements taken with inclinometer - Trunk flexion: 90°. Trunk extension: 15°. R trunk side-bend: 15°. L trunk side-bend 10° with pain on the right side. Cervical flexion: 60°. Cervical extension: 20° with pain. R cervical rotation: 55°. Left cervical rotation: 70°. R cervical side-bend: 25°. L cervical sidebend: 20°.
4
MMT – Bilateral upper extremity is grossly 4/5 bilaterally. Lower extremity is 4/5 bilaterally, except left hip extensors are 4-/5 and bilateral hip abductors (gluteus medius) are 3+/5. Palpation – Patient has increased tension and tenderness on bilateral upper trapezius, bilateral lumbar paraspinals, suboccipital muscles, left piriformis, bilateral scalenes left worse than right. Patient has an elevated left first rib. PA glides were hypomobile on segments C3-T3 and L1-L5 with no pain, all other segments WNL. Special tests – Spurlings compression test negative. Cervical distraction test: positive with relief of symptoms. Slump test: positive on the left. McKenzie test negative with no preferred direction. SLR to 85° on both sides with reported hamstring tightness. Pelvic asymmetry with R ASIS posteriorly rotated.
Evaluation Diagnosis PT diagnosis: 723.1 and 722.4 (cervicalgia and degeneration of cervical intervertebral disks respectively), 733.0 (osteoporosis), 724.3 (sciatica) all under pattern 4F.
Narrative Assessment The patient is a 57-year-old female who presents with deficits in ROM of spine, weakness of hip abductors bilaterally and left hip extensors, chronic sciatica symptoms, as well as signs and symptoms consistent with acute exacerbation secondary to chronic cervical degenerative disease. Patient has limited functional mobility due to pain. Secondarily, patient has chronic history of osteoporosis. Emotional issues and sedentary lifestyle may impede patient’s progress; however with a combination of manual therapy and a supervised exercise program patient will likely improve her symptoms and increase her physical fitness to better accomplish work tasks and ADLs.
Problem List 1. Weak abductors bilaterally and hip extensor on L 5
2. Deficits in AROM of spine shown in: Trunk extension: 15°. R trunk side-bend: 15°. L trunk sidebend: 10° with pain on the right side. Cervical flexion: 60°. Cervical extension: 20° with pain. R cervical rotation: 55°. 3. Limited nerve glide noted by positive Slump test on the left 4. High risk for fracture secondary to osteoporosis 5. Inability to do laundry, sit for more than 40 minutes, walk or stand for more than 20 minutes, yard work, and frequent sleep disturbances all secondary to pain.
Prognosis Prognosis for this patient is good, even though degenerative changes follow an inexorable progression patient can increase her ROM and strength deficits with physical therapy. Patient will be provided with education and interventions, which should help her better manage her symptoms as well as establish an exercise routine that if maintained long term can provide the patient with independent symptom relief.
Goals 1. Patient will increase MMT of gluteus medius to 4/5 and hip abductors to 5/5 bilaterally, to enable patient to perform yard work free of pain for 60 minutes, with a 10-minute rest break within 12 weeks. Short-term goal: Patient will demonstrate working knowledge of lifting mechanics, by demonstrating 3 out of 5 lifts correctly to therapist by third PT visit. 2. Decrease Neck and Back index by 20% or more within 10 weeks to show improvements in functional mobility. Short-term goal: Patient will increase standing tolerance to 40 minutes with 0/10 pain facilitated by deep core stabilizers and multifidus’ activation, 3 out of 5 times a day (4 weeks).
6
3. Patient will sleep seven continuous hours without pain disturbances. This will be achieved 4/7 times a week by gains in ROM, joint functional mobility, and strengthening exercises. (10 weeks) Short-term goal: Patient will be independent with home exercise program, she will demonstrate her HEP to therapist correctly 5/5 times, within 1 week. 4. Patient will increase sitting tolerance to 60 minutes with 2/10 pain by changing work station ergonomics and activating transversus and multifidus with an alarm setting in her computer. ‘Core activation’ alarm will be set for every ten minutes. Short-Term goal: Patient will perform core activation (combination of transversus, Kegel and multifidus) with neutral spine measured by pressure cuff 4/5 times correctly, within two weeks.
Plan of Care Patient will be seen for physical therapy 2 times a week for six weeks. Patient will benefit from physical therapy, which will focus on therapeutic exercise to improve ROM, strength, increase tolerance for functional activities and postural endurance to allow patient to return to independence with yard work, home tasks, and work related activities. Manual therapy and muscle energy technique to be administered to cervical, thoracic and pelvic region to improve patient’s functional mobility. Sciatica nerve flossing focused on left side to help decrease pain symptoms. Modalities as needed for patient’s comfort and pain control. Lastly, a home exercise program will be provided in verbal and written form specifically tailored to address patient’s management of osteoporosis’ progression.
Interventions PATIENT RELATED INSTRUCTIONS Patient will be instructed verbally, by demonstration and via written material her home exercise program and in clinic program. Additionally, patient will follow up with therapy sessions every 2 months after discharge to be appropriately progressed in her exercises.
7
IN CLINIC MANUAL THERAPY AND SUPERVISED EXERCISE PROGRAM: Patient will receive thirty minutes of manual therapy followed by thirty minutes of supervised exercises. Manual therapy for cervical spine and thoracic spine: •
MET to cervical and thoracic spine
•
PA glides, grade 2-3 on C7-T3 and L1-L5
•
Backward nodding
•
Manual cervical traction
•
Soft tissue release to suboccipitals, scalenes, trapezius and rhomboids.
Exercises: •
Craniocervical flexion exercises performed with pressure cuff for biofeedback
•
‘Core 3’ exercises performed in sitting position with foam roll: scapula retractions/ protractions, alternating shoulder flexion and extension while pushing into foam roll, and snow angels.
•
Dumbbell shrugs, bent over rows, ‘hug a tree’ with red tube, and serratus punches. Scapula retraction and depression with Theraband.
•
Transversus activation with medicine ball (for 3 minutes with alternating 10 second holds and 5 second rests), Kegels exercises, multifidus activation begin with supine heel digs progress to all fours alternating knee lifts
•
Bridging, side lying clam shells with weights, and prone hip extension with ankle weights
•
Nerve glides in slump position on left side
8
•
Patient education on postural awareness about issues stemming from forward head posture, proper ergonomics of workstation at home, a handout for HEP as well as a handout on how to make proper adjustments to her home workstation
HOME EXERCISE PROGRAM Walks with weighted vests for 30 minutes, 3 times a week.
COORDINATION AND COMMUNICATION WITH OTHER HEALTH PROFESSIONALS Discuss with her nutritionist her gluten free diet and how to create a diverse and varied menu that would help the patient form new food habits and maintain these changes long term. Patient will also contact her primary care physician and discuss the exercise plan, with any anticipated concerns with her cardiovascular health or overall health state that could interfere with an increase in physical activity.
FAMILY RELATED INSTRUCTIONS Meet with patient’s husband to discuss possible concerns and questions about these lifestyle changes, with increased activity and brainstorm ideas on how to adapt these exercises into their busy travel schedule.
Outcomes Patient was seen for four weeks and has two remaining sessions, however due to personal travel plans patient will be returning to physical therapy in two months to resume her sessions. Patient has maintained her walks with a frequency of at least twice a week, for three out of the four weeks she has been seen for physical therapy. Home workstation has been modified according to directions provided by therapist and patient has reported increased tolerance to seated work from 40 to 50 minutes. Patient reports decrease in pain from 8/10 during standing and yard activities to 4/10 provided she remembers to activate her deep core muscles, and performs proper lifting techniques. Goals for decrease in Neck and
9
Back Indices, decrease in sleep disturbances, and increase in MMT grade have not been met, but patient is making progress towards these goals. Measurement of BMD changes and effects of home exercise program were unavailable due to limited time of intervention as well as chronic osteoporosis not being the primary reason for patient’s physical therapy prescription. Therefore, it remains to be seen whether patient will comply with an exercise regimen for a minimum of twelve months in order to achieve measurable changes on her next DXA test.
10
Section 3: Review Evidence Based Analysis Implications of Osteoporosis Osteoporosis is a systemic skeletal disease and is not only characterized by low bone mass, but also by changes in the architecture of the bone itself leading to bone fragility.[23] Bone fragility increases the individual’s risk for fractures, and in many cases a fall will lead to a hip or wrist fracture along with multiple complications, which could in some cases result in death. According to Center for Disease Control and Prevention, one in every three adults age 65 or older fall every year. The National Osteoporosis Foundation (NOF) estimates that 52 million Americans have osteoporosis and low bone density, and that approximately one in two women and up to one in four men aged fifty and older will have an osteoporosis related fracture. Osteoporosis, like other pathologies, has risk factors that must be considered, including modifiable and non-modifiable risk factors. According to the International Osteoporosis Foundation, some of the nonmodifiable factors are: age, female gender, family history of osteoporosis, ethnicity, menopause and hysterectomy. Exercise would fit under modifiable risk factors since a sedentary lifestyle will negatively affect BMD, as will smoking, poor diet, vitamin D deficiency and low body mass index. These latter factors will be examined briefly, while maintaining an emphasis on exercise and its effects, or lack thereof, on osteoporosis progression. The majority of studies reviewed in this particular case study cover the range of postmenopausal women ages 50-70, many of whom are at risk for falls and incurred fractures secondary to osteoporosis. There are major concerns supporting the need for osteoporosis research, which include an aging population, the concern over a disease that is becoming epidemic, and the health costs involved in treatment of osteoporotic fractures. Moreover, with the pending silver tsunami from our aging population,
11
osteoporotic fractures are being referred by some as a ‘time bomb’ with over six million projected hip fractures by the year 2050. [9]
Pharmacological Interventions Medications are usually the first line of treatment for osteoporosis. It is therefore important to briefly mention the main drugs currently prescribed to patients. As with all drugs, there are given limitations to long-term use, and risk benefit ratios often indicate more risks than benefits. Some problems inherent with medications include severe side effects, high costs, and low compliance. The drug treatments fall into two main categories: antiresorptive medications and hormone therapy. Biphosphonates are antiresorptive medications with alendronate, risedronate, ibandronate, and zoledronic acid offered as the first line of treatment of osteoporosis. These can be taken orally or intravenously with the latter presenting less compliance issues. [16] As the name implies, antiresorptive drugs work by binding to bone and getting internalized by osteoclasts to inhibit break down of bone. [13] Hormone therapy can be via estrogen monotherapy or combined estrogen and progestin therapy. Estrogen is also widely prescribed, usually at the onset of menopause; estrogen then requires long term use in order to achieve the intended results. [11] Systematic review by MacLean et al. [13] has demonstrated that biphosphonates and estrogen therapy may prevent fractures in postmenopausal women who are at high risk for fractures (t-scores < -2.5 SD or previous osteoporotic fracture). However, these positive findings of biphosphonates are limited to a specific high risk group of patients. Adverse events from the use of oral biphosphonates include gastrointestinal complications (esophageal ulcerations, perforations, bleeding episodes, nausea, vomiting), and risk of serious atrial fibrillation. Intravenous biphosphonates administered in high doses to cancer patients were associated in several published cases with osteonecrosis of the jaw. [13] Moreover, according to Lewieck, hormone therapy has been shown to effectively reduce the risk of
12
fracture by 30-40% when compared to placebo results. Side effects include higher risk of CVA, cardiac events, venous thromboembolic events and small but significant breast cancer risk. Conclusively, articles reviewing the safety and effectiveness of biphosphonates and estrogen raised concerns about long-term use complications, with increased rate loss of BMD due to discontinuation of either drug. [13][11]
Diagnosing Osteoporosis: DXA vs. pQCT As previously mentioned, bone geometry is an important component of bone’s strength. Currently, a bone density measurement using dual-energy x-ray absorptiometry, or DXA, is the gold standard for diagnosis of osteoporosis. The T-scores are standard deviations greater or less than a mean value for a young adult, while Z-scores have a mean reference from an aged-matched individual. [19] The World Health Organization has a four diagnostic category based on T-scores: normal 0 – 0.99; osteopenia –1 to –2.49, osteoporosis: ≤ –2.5 (eg, –3.0, –4.0), severe or established osteoporosis: ≤ –2.5, with a fragility fracture. In the majority of studies, which attempted to assess the effects of exercise on osteoporosis progression, DXA measurements are the key outcome to examine the effects of exercise on bone density. However, DXA readings only account for areal bone mineral density (aBMD), which at best only describes 60-70% of the variance in ultimate strength of bone tissue. [17] This has brought researchers’ attention to the importance of depicting the whole picture when it comes to bone strength by adding to aBMD parameters of bone geometry. Geometric measurements of bone that assess bone structure and arrangement of bone mineral in the cortical versus trabecular compartments can be analyzed with quantitative computed tomography (QCT), peripheral quantitative computed tomography (pQCT), and magnetic resonance imaging (MRI). [17]
Research A solid body of evidence indicates exercise positively affects bone density through such mechanisms such as increased mechanical loading, lean mass stress on bone, and bone’s ability to adapt
13
to impact. According to Hamilton, adaptations tend to be site specific and more often influence cortical rather than trabecular components of bone. [7] Adami et al. define the importance of cortical bone volumetric changes to reflect an increase in the bending resistance of bone, an indicator of bone strength. [1] This particular study had a six-month duration and focused on geometric changes of the ultradistal
radius in postmenopausal women. Exercises were designed to maximize stress on the wrist. Results were significant in exposing the limitation of DXA readings, which remained close to the same for both groups. Conversely, pQCT measurements indicated significant geometric changes and reshaping of bone at the ultradistal radius in the intervention group. A systematic review (SR) by Polidoulis [17], which considered the above mentioned geometric measurements concluded that lower extremity exercises provided small, but significant changes in trabecular volumetric bone mineral density (TrvBMD) of distal tibia as well as an increase in cortical volumetric BMD of the tibial shaft. Subgroup analysis of studies included in this SR indicated that longer duration of intervention, meaning at least a year, and fewer years in post-menopause, were both characteristics that provided significant changes in CvBMD. The systematic review just mentioned demonstrates that exercise indeed decreases the rate of bone loss, and therefore slows the progression of osteoporosis. Furthermore, the SR helped establish how often and how long sessions should take place. Four out of six RCTs reviewed used twelve months as their intervention duration, with sessions taking place three to five times per week and lasting 50 to 60 minutes. Unfortunately, the review neither sufficiently described the exercise series, nor how patients were taught to perform them and at what intensity levels (1RM, HRmax), all of which are important factors to create a consistent, measurable, and repeatable intervention. This problem is often encountered when reviewing the literature on recommended exercise interventions for osteoporosis management; studies either lack detail or encompass such great diversity of exercises that one homogeneous exercise prescription becomes a
14
challenge. The Engelke longitudinal study published in 2005 was most helpful in defining a specific set of exercises combining high impact exercises and resistance training. The study took place in Erlangen with postmenopausal women and lasted three years. The supervised sessions in the Engelke et al. [6] study were subdivided into fours parts: warm-up and endurance sequence, jumping sequence, strength training sequence, and flexibility training sequence. Warm-up sequence was comprised of running and high impact aerobics. Heart rate during running activity was initially maintained at 65% and progressed to 75%-85% for the remainder of warm up. Six months after the start of intervention the jumping sequence was added, with 4 sets of rope skipping exercises. Strength training comprised of exercises on machines for all main muscle groups, followed by isometrics and conditioning with elastic belts, dumbbells, and weighted vests. Intensity of exercise training alternated between high and low periods. Twelve weeks of high intensity training were interspersed with 4-5 weeks of low intensity. Finally, high intensity training was maintained at 70%-92.5% 1 RM, and low intensity at 50% 1 RM. Flexibility sequence had subjects perform passive stretching for all main muscle groups. The results demonstrated significant maintenance of bone density in the intervention group on lumbar spine, hip and calcaneus (except at the forearm) when compared to the control group. [6] The study concluded that a low-volume/ high-intensity exercise program can effectively arrest the decrease in BMD. Exercise is appealing for being non-invasive, non-pharmacological and affordable. However, patient compliance poses a great challenge for improvements to be gained, maintained, and documented over the long term. Most studies examining exercise as an intervention for osteoporosis reflect the challenge of producing prescriptions that are both practical, appealing, and reproducible. Additionally, adequate duration of a given intervention is of paramount importance. Apathy and attrition of participants greatly affects the quality of studies. Furthermore, the type of exercise routine dictates which (if any)
15
improvements are possible, and oversimplification of intervention can sacrifice improvements over time. Schmitt et al. [20] illustrated this adherence conundrum by showing that affordable and popular programs such as Tai Chi, aerobics and walking are less effective at slowing the progression of osteoporosis. As another example, a randomized controlled trial done in Japan by Sakai et al. [19] investigated the effects of unipedal standing exercise on bone mineral density. Once again, authors in part chose unipedal stance as the main intervention for its simplicity and affordability. Moreover, one minute of unipedal stance is comparable to the amount of integral load gained when walking for 53 minutes.[19] Participants were instructed to perform one-legged stance for one minute on each leg, three times per day for 6 months. Despite the intervention’s straightforwardness, the study unfortunately concluded no improvement in BMD of the hip (except for patient’s seventy or older (p=0.034)), further illustrating the need to tailor prescriptions for numerous patient variables. The subject of this case study was advised by her primary care physician to walk in order to slow the progression of her osteoporosis. Research however does not support walking as a single exercise therapy for diminishing bone loss in postmenopausal women.[14] On the other hand, according to Bergstrom et al., walking in combination with resistive training has demonstrated a small but positive effect on hip BMD (p=0.066) in postmenopausal women.[3] Results however are conflicted; a meta-analysis by Martin St James and Carrol [14] demonstrated that walking produced no significant effect on lumbar spine BMD and a small statistically significant change in BMD of the femoral neck. In an effort to apply these positive findings to her particular case, the subject patient was given a home exercise regimen of 40-60 minute walks three times a week with a weighted vest. However, the patient expected difficulty maintaining this amount of activity on her own, and therefore the program was reduced to 30 minutes to adapt to her needs. The recommendation of added weighted vests was based upon Wolff’s Law that bone will adapt to increases in load. Additionally, a lower quality study of a long-term
16
(5 year) exercise program by Snow et al. involving jumps with weighted vests demonstrated that controls lost BMD at the femoral neck, trochanter and total hip while the intervention group maintained BMD in all these regions. [21] A population based randomized control study by Vainionpaa [23] in Finland reported measurable adaptations of bone most prominent at the mid femur after twelve months of impact exercises. This trial had 120 participants who were premenopausal women with in clinic intervention comprised of step patterns, stamping, jumping, running and walking for 60 minutes, 3 times a week. Authors did not provide further specifications on intensity or sets performed in supervised sessions, and home exercise program was broadly described as 10 minutes of similar exercise patterns as those practiced in clinic. Findings were significant for 0.2% gain in mean bone circumference of mid femur compared to control group, and gains in muscle cross section area at proximal tibia (2.4%) and mid femur (1.2%). This study also highlighted the importance of high compliance for measurable gains to occur. Subgroup analysis of the exercise group reported increased gains in bone circumference and cortical cross section area in subjects who participated in >66 sessions compared to subjects with