The Relationship Between Range of Movement, Flexibility, and ...

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Topics in Geriatric Rehabilitation Vol. 26, No. 2, pp. 147–154 c 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright 

The Relationship Between Range of Movement, Flexibility, and Balance in the Elderly Michael Chiacchiero, PT, DPT; Bethany Dresely, DPT; Udani Silva, DPT; Ramone DeLosReyes, DPT; Boris Vorik, DPT This study investigated whether decreased passive lower extremity range of motion (ROM) and flexibility contribute to falls in the elderly. Eighteen subjects aged 60 years and older participated in the study. The subjects were divided into 2 categories, fallers and nonfallers. Both subject groups underwent ROM and flexibility testing of the lower extremity. A statistically significant decrease of ROM of hip extension, internal rotation, abduction, ankle dorsiflexion, and gastrocnemius length was found in the faller group as compared with the nonfaller group. The findings of this study suggest a link between decreased ROM and falls in the elderly and that addressing ROM deficits may decrease potential falls. Key words: balance, elderly, falls, flexibility, passive range of motion

F

ALLS are among the leading causes of fatal and nonfatal injuries in the elderly.1 More than 20 billion dollars are spent annually for the care of the elderly with fall-related injuries, and this figure has been projected to cost up to 37 billion dollars by the year 2020. Information from the Centers for Disease Control and Prevention showed that the risk of falls increases with age. In 2001, adults older than 85 years were 4 to 5 times more likely

to suffer a fall-related injury than adults aged between 65 and 74 years.1 Balance is the ability to maintain the body’s center of mass (COM) within the limits of the base of support.2 Depending on the motor task, people use 3 different strategies to maintain their upright posture. These are known as ankle, hip, and step strategies. Both hip and ankle strategies involve activation of hip and ankle muscles opposite to the direction of the perturbation.2 When the amplitude of the perturbation is too large, the step strategy is utilized. The step strategy is performed by taking a step in the direction of the perturbation, although the base of support is realigned under the COM. This allows maintenance of the COM within the base of support preventing external forces to disturb balance and thus maintain upright posture.2 Although these systems and strategies help to maintain the balance of younger people, they become less effective in the elderly population because of physiological changes. For example, a study performed on animals has shown that the increase in connective tissue in the aging muscle would lead to a decrease in flexibility.3 In addition, the muscle

This research was completed in partial fulfillment for the doctorate in physical therapy degree (DPT) for the last 4 authors (B.D., U.S., R.D., and B.V.) from the College of Staten Island/Graduate Center of The City University of New York. Author Affiliation: College of Staten Island, Staten Island, New York. We thank Professors Maria Knikou, Zagloul Ahmed, and Jeff Rothman from the College of Staten Island for all their help, guidance, and support throughout the entire research process. We also thank the rehabilitation staff of Carmel Richmond Nursing Home, especially Alex Lakhter, and all subjects who volunteered in this study. Corresponding Author: Michael Chiacchiero, PT, DPT, College of Staten Island, 2800 Victory Blvd, Staten Island, NY 10314 ([email protected]).

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production force is decreased.4 Aging results in a decrement of muscle cross-sectional area and the volume of connective tissue. Furthermore, the decrease in type II fast twitch muscle fibers would hinder the ability of the muscle to create a fast forceful contraction.4 The aforementioned physiological modifications result in kinematic changes of the musculoskeletal system. There is a 50% loss of trunk extensor flexibility after the age of 70 years, which results in COM displacement posterior to the heels. In addition, ankle joint flexibility decreases by 50% in women and 35% in men after 55 years of age.2 Normal functioning of the musculoskeletal system is imperative for balance maintenance. The decreased flexibility and strength in the elderly also decrease their ability to recover quickly from a perturbation. Lack of necessary range of motion (ROM) would decrease the effectiveness of hip and ankle strategies. If a person is unable to counteract a perturbation due to lack of flexibility and lack of appropriate ROM, the perturbation may result in fall. Prior research has shown that there is correlation between short gastrocnemius muscle and increased falls in the elderly.5 The objectives of this research study were to establish the relation of ROM and flexibility of all major muscle groups of the legs and to establish whether ROM and flexibility affect the balance in the elderly population with falls. Findings from the elderly susceptible to falls were compared with the findings from the elderly without falls. We hypothesized that the ROM of the hip, knee, and ankle contributes to balance maintenance and thus their decreased values are strongly associated with falls.

METHODS Subjects Twenty-one subjects (11 women and 10 men; 10 nonfallers and 11 fallers) between the ages of 60 and 93 years participated in this study. Subjects were classified as fallers if they reported 2 or more falls over the

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Table 1. subject characteristics Nonfallers subjects

Fallers subjects

Subject Age, Subject No. y Gender No. Age Gender s1 74 s2 77 s3 78 s4 84 s6 87 s7 75 s8 92 s9 90 s10 75 Average 81.33 SD 7.0

M F F M M F M F F

s1 83 s2 79 s3 81 s4 93 s5 60 s6 80 s7 82 s8 80 s9 87 Average 80.55 SD 8.9

M M M M F F F F F

Abbreviations: F, female; M, male.

past 12 months. Subject selection was performed by the supervising physical therapist at Carmel Richmond Nursing Home, who reviewed each subject’s medical history to verify his or her eligibility for the study. Selection criteria for participation included the following: over the age of 60 years, ambulatory, and full weight bearing with or without an assistive device. Subjects were excluded if they had a diagnosis of vestibular or central nervous system pathology, orthostatic hypotension, the inability to follow one step commands, or a fracture within the past year. All subjects participated voluntarily in this study and signed an informed consent form. The experimental protocol was approved by the institutional review board of the College of Staten Island. One subject was unable to complete the study secondary to complaints of supine and side-lying positions. Another subject was excluded because the results were unable to be assessed correctly secondary to spasticity. The last subject’s ROM could not be assessed correctly secondary to hyperaglesia in bilateral lower extremities. In Table 1, subjects’ characteristics are summarized. Changes were made to the methodology during the study to accommodate for patient discomfort. The Ober test was performed only

RANGE OF MOVEMENT, FLEXIBILITY, AND BALANCE IN THE ELDERLY

in subjects who were able to understand the verbal commands for bed mobility that was required. Furthermore, the Thomas test was performed only once on each lower extremity of each subject because of difficulty and discomfort in the testing position. One subject was excluded from the Thomas test because of a medical history of multiple disc herniations. Eversion values were omitted in 6 subjects because of skewed data attained for ROM values. Experimental procedures The study consisted of one 40- to 60-minute session at Carmel Richmond Nursing Home. Each subject participated in 4 separate tests: the Timed Get Up and Go, the Functional Reach Test, Range of Motion Testing, and Muscle Length Testing. Timed Get Up and Go For each subject, the time needed to walk at a normal speed for 6 m was measured. The amount of time it took the subjects to perform this test was recorded. Functional Reach Test A tape measure was fixed to the wall so that it lined up with each subject’s acromion process. Each subject was given specific directions to “lean forward and without moving your feet reach as far as you can and try to keep your hand along the wall.” No assistive devices were used for stability. The subject was asked to perform this test a total of 3 times. The amount of movement the subject demonstrated was recorded in inches and compared to the age-related normal statistics. Range of Motion Testing Range of motion of the hip, knee, and ankle was measured using a goniometer based on standardized techniques. Range of motion was tested for hip flexion, extension, abduction, adduction, internal rotation, external rotation; knee flexion and extension;

and ankle plantarflexion, dorsiflexion, inversion, and eversion. Each ROM was measured 3 times. Muscle Length Testing Muscle length testing of the iliopsoas, iliotibial band, hamstrings, and gastrocnemius were measured using a goniometer with the muscle isolated and maximally lengthened. The Ober test provides us information about the length of the tensor fascia lata muscle, whereas the Thomas test provides information about the length of the rectus femoris muscle. The order of testing was Ober test, straight leg raise, gastrocnemius, and Thomas test. Data analysis For each subject, the ROM, flexibility, and balance tests were normalized to the standard values that correspond to values from measurement of joint motion.6 To normalize the data, each subject’s ROM was converted into a percentage of normal using the following equation: (subject ROM/normal ROM) × 100. This percentage was converted to a score from 0 to 10 according to Table 2. A paired t test was utilized to establish statistically significant differences between fallers and Table 2. Index conversion chart ROM, flexibility, and FR

TUG

% of normal 0 1 2 3 4 5 6 7 8 9 10

100

No. of seconds 10 9 8 7 6 5 4 3 2 1 0

49

Abbreviations: FR, functional reach; ROM, range of motion; TUG, Timed Up and Go test.

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Figure 1. Comparison of average flexibility score for nonfallers and fallers. Data are mean ± SD. Significantly decreased flexibility in fallers for gastrocnemius and overall flexibility (P > .05). a Significant difference between fallers and nonfallers. Gastroc indicates gastrocnemius; TFL, tensor fascia lata.

nonfallers for each variable measured (eg, ROM, balance, and flexibility). A linear regression was conducted between balance to ROM and flexibility. RESULTS In Figure 1 and Table 3, the overall amplitude of the flexibility score, along with the standard deviation of the average, is indicated for the gastrocnemius, hamstrings, rectus femoris, and tensor fascia muscles for both subject groups (nonfallers and fallers). A paired t test conducted for each muscle sepTable 3. Flexibility in fallers and nonfallers

Gastrocnemius Hamstrings Rectus femoris Tensor fascia data Average a Significant

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Nonfallers, M ± SD

Fallers, M ± SD

P

4.67 ± 3.5 6.89 ± 0.9 8.33 ± 3.2 3.5 ± 1.0 6.28 ± 1.3

1.89 ± 2.5 6.67 ± 1.2 8.00 ± 3.1 3.14 ± 0.7 5.10 ± 1.5

.036a .335 .411 .249 .048a

difference between nonfallers and fallers.

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arately between subject groups showed that in the nonfaller group the flexibility score was significantly higher than that in the faller group in the gastrocnemius muscle (P < .05) and overall (see last columns of Fig 1). In Figure 2 and Table 4, the overall amplitude of the ROM score for both subject groups along with the standard deviation of the mean is indicated. The ROM score was statistically significant lower in the faller group than in the nonfaller group (P < .05). This was the case for hip extension, hip abduction (Hip Abd), hip internal rotation (Hip IR), and ankle dorsiflexion (P < .05). Figure 3 shows the linear regression analysis of combined balance score obtained from FR and TUG tests versus the average flexibility and ROM scores. There was no significance found between balance and flexibility/ROM (nonfaller: R2 = 0.0407, fallers: R2 = 0.0378). DISCUSSION It has been shown that the increased propensity for falling in the elderly is the result of deficiencies in multiple systems. The

RANGE OF MOVEMENT, FLEXIBILITY, AND BALANCE IN THE ELDERLY

Figure 2. Comparison of average ROM score for nonfallers and fallers. Data are mean ± SD. Significantly decreased ROM in fallers for hip extension, hip internal rotation, hip abduction, ankle dorsiflexion, and overall ROM (P > .05). a Significant difference between fallers and nonfallers. Abd indicates abduction; Add, adduction; DF, dorsiflexion; ER, external rotation; EV, eversion; ext, extension; flex, flexion; IN, inversion; IR, internal rotation; PF, plantar flexion; ROM, range of motion.

impairments of the vestibular, visual, and somatosensory systems in the elderly are major causes for increased falls and decreased balance.2 For example, the elderly exhibit an increase in sensory threshold and decreased tactile sensitivity for fine touch and pressure/

vibration secondary to receptor loss at the ankle and foot.7 These changes associated with the elderly will decrease their ability to sense external perturbations and therefore effectively employ the ankle strategy.8 The elderly rely upon alternative strategies such as

Table 4. ROM in fallers and nonfallers

Hip extension Hip flexion Hip external rotation Hip internal rotation Hip abduction Hip adduction Knee flexion Knee extension Ankle dorsiflexion Ankle plantarflexion Ankle inversion Ankle eversion Average a Significant

Nonfallers, M ± SD

Fallers, M ± SD

P

5.56 ± 1.1 7.89 ± 0.8 4.67 ± 0.7 7.33 ± 1.0 5.56 ± 1.0 7.22 ± 1.1 8.56 ± 0.9 9.56 ± 1.3 7.22 ± 1.9 9.22 ± 1.4 8.78 ± 1.3 3.89 ± 3.8 7.41 ± 0.4

2 ± 1.7 7.56 ± 0.7 4.44 ± 1.0 6.11 ± 1.8 3.78 ± 0.8 6.67 ± 1.3 8.11 ± 1.0 9.11 ± 2.7 4.89 ± 1.9 9.22 ± 0.8 7.67 ± 2.4 5.11 ± 3.5 6.20 ± 0.6

4.77E-05a .181 .295 .045a .0004a .172 .173 .330 .010a .5 0.120 0.243 0.0005a

difference between nonfallers and fallers.

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Figure 3. Comparison of average flexibility/ROM score vs the average balance score for all subjects. No significant interaction (nonfaller: R2 = 0.0407, fallers: R2 = 0.0378). ROM indicates range of motion.

the hip strategy for even minor perturbations that a normal healthy adult would be able to compensate for utilizing the ankle strategy.9 These changes result in the increased need for the musculoskeletal system to function at an optimal level. The findings of this study show that the elderly have decreased flexibility and ROM, which would impede their ability to regain balance following an external perturbation. Range of motion for hip extension, hip internal rotation, hip abduction, ankle dorsiflexion, gastrocnemius length, and general flexibility were significantly decreased in elderly fallers older than 60 years. The reduction in hip extension combined with an anterior tilt of the pelvis and resultant restricted hip musculature is a primary reason for a decrease in stride length and walking speed in elderly fallers.10 The aforementioned mechanism that may cause a decrease in stride length could also contribute to increased risk of falls. A study by Kerrigan et al10 has shown that there is a correlation between decreased stride length and increased risk of falls. In addition, an increase in the anterior pelvic tilt found in fallers would lead to a displacement of the center of gravity out of the base of support resulting in a greater

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likelihood of falls. The ability of the elderly to use the hip strategy effectively is even more paramount, since they use the hip strategy more often than the ankle strategy because of biomechanical pathologies and loss of somatosensory function at the ankle.8 The aforementioned somatosensory deficiencies at the ankle coupled with our findings showed a significant decrease in ankle dorsiflexion (DF) and gastrocnemius length that can lead to deleterious effects on balance recovery. These results are further supported by Nolan et al5 and Whipple et al,11 who also concluded that decreased DF and decreased length of knee and ankle muscles were causative factors for falls. The adverse muscle length tension relationship created by muscle tautness would lead to an elderly person’s decreased ability to create adequate torque for balance recovery. ROM and flexibility overall were also found to be significantly decreased in fallers as compared with nonfallers (Figs. 1 and 2). A possible explanation for these findings is the decreased activation of the muscle spindle as a result of decreased stretch in the muscle. This may lead to decreased amplitude of the stretch reflex that would impact the

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successful use of the stretch reflex to regain balance.2 Our results found a significant decrease in ROM at the hip, without a decrease in muscle length. We speculate that the taut hip capsule would prevent elderly fallers from stretching the muscle with external perturbation; therefore, the stretch reflex is not activated properly to prevent falls. Although it is tempting to speculate that decrements in the ROM of hip abduction and hip IR are directly correlated with falling in the elderly, the cause for this relationship has not been adequately studied. However, since decreased pelvic flexibility is correlated to the reduced speed of walking and decreased step length, the possibility of falls is increased and it stands to reason that the decrease in hip IR observed may result in a higher incidence of falls.12,13 This can provide a plausible explanation for the lack of hip internal rotation in fallers. In addition, a study by Maki and McIlory14 proposed that a decrease in hip abduction would decrease a person’s ability to contain his or her COM over his or her base of support (BOS) during the stance phase of gait. In subjects with decreased hip abduction, the COM was shifted more toward the swing leg rather than toward the standing,14 suggesting that hip abduction is a necessary component for maintaining a proper COM. Although a significant correlation was found when comparing fallers and nonfallers with regards to ROM and flexibility, there was no significance between the balance tests and ROM. These results may be because the balance tests utilized in this study were not fully comprehensive to assess balance in this particular population. Furthermore, it is possible that some subjects did not fully understand the verbal commands for the TUG and the functional reach test, which prevented them from performing the tests correctly. The findings of the present study suggest that there are limitations in specific hip and ankle motions that may contribute to musculoskeletal deficiencies that result in loss of balance. A randomized controlled trial would need to be done in order to investigate whether implementing a stretching pro-

gram that focuses on the significant findings of this study, such as decreased hip extension, ankle DF, and decreased gastrocnemius length would result in improved balance in the elderly. Assessing and treating flexibility in the lower extremity may have important implications for improving the quality of rehabilitation services for the elderly with balance impairments. Another important factor to be considered is the distribution of forces. It is important to examine distribution forces during balance tests to determine which strategy is being utilized most during ambulation and forward reaching. The utilization of force plates would provide objective results to validate which strategies are being used more in elderly populations. These findings can be used in conjunction with ROM measurements to provide relevant information about the mobility of the joints and how it affects different balance maintenance strategies. The use of the TUG and FR as balance tests was a limitation of this study. Using a more comprehensive test such as the Berg Balance Test, the Tinetti Assessment Tool, or a more objective method such as force plates would have allowed for a more accurate measure of the subject’s balance. Dynamic balance scales provide a functional assessment of a person’s balance capability. By using the Berg Balance Scale or the Tinetti balance scale, the findings would yield more functional, reliable, and objective results and further validate the results of the current study. In addition, increasing the number of subjects and using subjects from different settings such as community ambulators rather than residents of a nursing home would further improve the study.

FUTURE STUDIES Further research is required to expand the theories of the current study. A potential study can investigate the effects of spinal mobility on balance and falls in the elderly. Instead of measuring ROM of the lower extremities, the researchers would assess spinal mobility

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between fallers and nonfallers in the elderly. The data collected from this study would determine the effects of spinal mobility on balance and falls in the elderly population. Evaluating and treating spinal mobility may have important implications for improving the quality of rehabilitation services for the elderly with balance impairments. Physical therapists can benefit from the study results by utilizing them to improve the treatment of patients with balance impairments. The findings of this study imply the importance of addressing ROM and flexibility deficits in the elderly fallers. Many rehabilitation protocols for decreased balance are focused on improving the somatosensory and vestibular systems; however, based on our re-

search findings, decrements in ROM and flexibility also play a role in falling. Since decreased flexibility is not the only cause for falling, focusing on the motions and muscles that this study found to be significant would allow for more efficient and effective management of elderly fallers. For patients who have balance problems, ROM of proximal and distal muscles need to be tested as they may affect their balance. In this respect, hip and ankle muscles appear to contribute to falls and thus the ROM of these muscles should be substantiated. In conclusion, our findings suggest that deficiencies in flexibility and ROM in the elderly are correlated with the increased frequency of falls.

REFERENCES 1. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. Web-based injury statistics query and reporting system (WISQARS) [online]. www.cdc.gov/ncipc/ factsheets/adultfalls..htm Published 2008. 2. Shumway-Cook A, Marjorie WH. Motor Control Translating Research Into Clinical Practice. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:159, 219. 3. Alnaqeeb MA, Al Zaid NS, Goldspink G. Connective tissue changes and physical properties of developing and ageing skeletal muscle. J Anatomy. 1984;139: 677–689. 4. Williams GN, Higgins MJ, Lewek MD Aging skeletal muscle: physiologic changes and the effects of training. Phys Ther. 2002;82:62–68. 5. Nolan MA, Nelson NJ, Rothman J. A comparison of ankle range of motion and flexibility in older women, fallers, and nonfallers. Top Geriatr Rehab. 1996;12:70–76. 6. Norkin CC, White DJ. Measurement of Joint Motion: A Guide to Goniometry. 3rd ed. Philadelphia, PA: FA Davis Co; 2003. 7. Kenshalo DR. Aging Effects on Cutaneous and Kinesthetic Sensibilities. Ann Arbor: University of Michigan; 1979.

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8. Horak F, Shupert C, Mirka A Components of postural dyscontrol in the elderly: a review. Neurobiol Aging. 1989;10:727–745. 9. Woollacott M, Inglin B, Manchester D. Response preparation and postural control: neuromuscular changes in the older adult. Ann NY Acad Sci. 1988; 515:42–53. 10. Kerrigan DC, Lee LW, Collins JL, Riley PO, Lipsitz LA Reduced hip extension during walking: healthy elderly and fallers versus young adults. Arch Phys Med Rehab. 2001;82:26–30. 11. Whipple RH, Wolfson LI, Amerman PM. The relationship of the knee and ankle weakness to falls in nursing home residents: an isokinetic study. J Am Geriatr Soc. 1987;35:13–20. 12. Christiansen C. The effects of hip and ankle stretching on gait function of older people. Arch Phys Med Rehab. 2008;89:1421–1428. 13. Rodacki ALF, Souza RM, Ugrinowitsch C, Cristopoliski F, Fowler NE. Transient effects of stretching exercises on gait parameters of elderly women. Manual Ther. 2009;14:167– 172. 14. Maki B, McIlroy W. The role of limb movements in maintaining upright stance: the “change-in-support” strategy. Phys Ther. 1997;77:488–505.