There are 1.3 million people in the United States living with limb loss.1 The majority of these amputations are in the lower limb with above- and below-knee amputations.2 Upper-limb amputations are primarily below the elbow.2 The least frequent amputation levels include elbow and shoulder disarticulations.2 A shoulder disarticulation procedure is the surgical separation of the entire arm from the shoulder joint without cutting bone. In this surgery, the humerus bone and the entire arm are removed from the scapula and the clavicle.1 Upper-limb specialists estimate the incidence of this procedure as an average of 5.08 patients per year since 2005.1 Because of the low incidence and traumatic result of this injury, the health care team faces a greater challenge when returning the patient to optimal function. For example, prosthetists face challenges with creating the interface for a shoulder disarticulation due to the proximal position of the prosthesis, less anatomic prominences for suspension, greater skin coverage, triaxial dynamic loading changes, amputation variability, increased weight, and cosmetic concerns.1 As a result of these inherent challenges, patients may face prosthetic rejection with rates as high as 39% to 65%.1 It is therefore imperative that the health care team must collaborate to help prevent rejection to ensure optimal patient function with this rare traumatic amputation.
Along with high prosthetic rejection rates, these patients will often face secondary impairments such as phantom limb pain (PLP) and chronic residual limb pain.1 Phantom limb pain is defined as nerve endings at the site of amputation that continue to send pain signals to the brain, which makes the brain think the limb is still functional.3 Sometimes the brain’s memory of pain is retained and interpreted as actual pain, regardless of signal from injured nerves.3 Residual limb pain is located at the end of the residual limb and is typically described as “burning” pain.3 Other sensations such as numbness, tingling, cramping, heat, pressure, and cold in a portion of the residual limb may accompany PLP and chronic residual limb pain.3 Each year in the United States, there are over 130,000 limb amputations with nearly every case experiencing some form of PLP.4 Approximately 75% of all patients who experience PLP will develop one of more of these symptoms within the first 24 hr or immediately after surgery.5 The intensity of pain can be relieved over time; however, cases of persistent pain or even increased pain have been reported.6
There is a broad spectrum of treatment options for patients with PLP and chronic residual limb pain including mirror therapy, biofeedback, and tactile sensory feedback. One of the more successful treatment strategies is mirror therapy, which was first described by Ramachandran and Rogers-Ramachandran7 in 1996. Mirror therapy is based on the concept that the visual feedback regarding the missing limb enhances the mind’s awareness of the phantom limb.7 Ramachandran and Rogers-Ramachandran7 hypothesized that every time a patient attempted to move the limb, he or she received visual and proprioceptive feedback that the limb did not in fact move. This feedback stamped itself into the brain circuitry even when the limb was no longer present.7 The concept of mirror therapy by Ramachandran and Rogers-Ramachandran7 is controversial regarding its effectiveness. In a study by Chan et al.8 on effectiveness of mirror therapy, 18 subjects were randomly placed into three groups (mirror group viewed intact foot, group that viewed a covered mirror, and one that trained in mental visualization). Patients in the mirror group attempted to perform movements with the amputated limb while viewing the reflected image of the movement of their intact limb.8 Patients in the covered mirror group attempted to perform movements with both their intact and amputated limbs when the mirror was covered by an opaque sheet. Patients in the mental visualization group closed their eyes and imagined performing movements with their amputated limb. The study concluded that after 4 weeks with 15-minute daily sessions, 100% of the patients in the mirror group reported a decrease in pain and pain episodes.8 In contrast, 50% of the patients in the opaque mirror group had increased pain; in the imagery group, 33% of the patients reported decreased pain, whereas 67% of the latter 2 groups reported an increase in pain.8 The findings from this study showed that mirror therapy every day for 15 minutes for 4 weeks reduced PLP and that opaque mirror therapy could actually increase pain levels. This study demonstrates the effective use of mirror therapy in the treatment of PLP.
Another approach to addressing PLP is the use of biofeedback training. Electromyography (EMG) studies have demonstrated that major muscles in the residual limb tense up several seconds before the cramping pain begins and that these muscles remain tense for much of the duration of the episode.9 Because of this pattern of tensing muscles in conjunction with pain, Sherman and Sherman9 conducted research and found that by decreasing the associated muscle spasm, the patients reported a decrease in PLP. A pilot study by Harden et al.10 examined the effectiveness of biofeedback in the treatment of nine individuals with pain who received up to seven biofeedback sessions over the course of 4 to 6 weeks. The study revealed that five of the nine patients in week 4 demonstrated a 20% reduction in pain according to the visual analog scale, and 7 patients in week 6 demonstrated a 30% reduction in PLP. The use of biofeedback has been shown to decrease muscle tension and pain and also to contribute to training muscles for prosthesis fitting.9 The biofeedback system conducts electricity from the skeletal muscles by voluntary contraction to the myoelectric electrodes for visual feedback to the patient. Electrodes are placed near the nerve innervation of the muscle to achieve maximum contraction potential. Depending on muscle contraction force, the therapist can set the electrode gain sensitivity appropriately between 1 and 7. If the electrode gain is set too low, the patient will struggle to produce an adequate signal, and control of the prosthesis could be very exhausting, causing fatigue. If the electrode gain is set too high, the patient can lose efficiency and cause the system to pick up other electric signals deeming the reading inaccurate.11 The biofeedback system also allows the amputee to practice control speed and grip force.11 To control speed, the digital system turns on once the patient reaches the set threshold amplitude. The digital hand speed and grip force are both proportional to muscle contraction.11 This means control is predictable for the patient and training should mimic these muscle contractions. Therefore, treatment should involve small and quick contractions for fine control, large sustained contractions for gross movements, constant speed to close the hand, and cocontraction to switch between hand rotations. The biofeedback system cannot train for adjusting grips, whereas the patient is required to manually adjust the thumb and fingers into different positions with the uninvolved arm. Grip force is proportionate to time and influenced by the compressibility of a grasped item.11 For example, harder objects need more time to increase grip force. Maximum grip force is limited electronically and not influenced by the intensity of muscle contraction but instead by the muscle’s ability to maximally contract and relax accordingly.11 The patient is trained in specific muscle contractions, and data are saved for proper fitting of the prosthesis. By utilizing the biofeedback system, the prosthetist and physical therapist can work together to record muscle control and fit the patient with the prosthesis accordingly. The goals of using biofeedback training for patients with PLP are to decrease muscle tension and pain, promote visual feedback on muscle control, and provide necessary information for the prosthetist to ensure an adequate myoelectric device most appropriate to the patient and his or her return to function.
Phantom limb and residual limb pain from a shoulder disarticulation can affect a person’s quality of life, self-confidence, and function. A study by Ostlie and Franklin12 demonstrated that upper-limb loss affected physical function evidenced by Disability of the Arm, Shoulder, and Hand (DASH) scores. A lower DASH score was associated with higher functioning, faster return to employment, and decreased postamputation time.12 To improve function and prevent secondary impairments of PLP, physical therapists could utilize the combined treatments of mirror therapy and electromyography biofeedback for a patient with a shoulder disarticulation.
The patient stands 5 ft, 8 in and weighs 160 lb. The patient is a Spanish-speaking male aged 48 years who lives in Phoenix, Arizona. The patient was injured on January 27, 2014, while working at a construction zone. The patient’s right arm was caught in a conveyer belt resulting in an upper-limb amputation and shoulder disarticulation with scapula and clavicle fracture.
Ethics approval for this case report was obtained from the University of St. Augustine for Health Sciences Institutional Review Board.
At initial evaluation, the patient arrived with his wife of 20 years, 15-year-old son, and translator. The patient walked into the clinic independently without an assistive device. The patient also seemed very rigid and protective of the right side of his body. The patient complained of the inability to write, complete household chores, garden, prepare a meal, manage transportation, sleep comfortably, and engage in sexual activities with his wife due to pain, lack of confidence, and decreased functional ability. The patient’s wife stated that her husband would not allow her to touch him at all due to pain and fear of reopening his scar. The patient was given a Numeric Pain Rating (NPR) scale to objectively document his pain progression throughout treatment. According to rehab measures, the NPR scale demonstrates excellent test-retest reliability for ratings on 2 or more days during the first week compared with week 2.13 It has been shown to be a reliable measure for pain intensity and unpleasantness and is sensitive to change in weeks after a major surgery.13 According to the NPR scale, the patient reported pain at his worst to be 9/10, pain at best to be 7/10, and current pain to be 8/10. The patient stated that his pain was best at 7/10 when he would lie on his opposite arm, rest, and take pain medication. The patient’s past medical history was unremarkable. The patient reported taking four pain pills a day as needed.
Structural inspection of the patient demonstrated rounded left shoulder with forward head posture. Incision site healed well with no residual openings. Skin near clavicle appeared frail and thin. Residual limb scar was dirty and not well cleaned (Figure 1). Patient reported he was afraid to touch the area in the shower due to fear of the scar opening. Upon attempted palpation of residual limb, the patient cringed at light touch palpation on the area. Because of apprehension and muscle guarding, the patient was unable to actively move the residual limb. Therefore, passive range of motion was deferred at that time due to patient uneasiness.
Biofeedback analysis of residual infraspinatus and pectoral muscles showed minimal contraction. The biofeedback system has electrodes to transmit contractions of desired muscles to a computer screen with visual feedback to give the patient constant feedback. The electrodes can be set to certain gain ratios with the number 7 being the most sensitive and most responsive to contraction and the number 1 being the least sensitive to contraction (Figures 2, 3). Ideally, a patient will be able to contract a muscle with a gain of 5 with adequate control and amplitude of 60. If the gain is set too high, it can impair the control of the prosthesis and increase risk for interference. The patient was able to produce a minimal contraction with amplitude averaging 16 to 20 of the infraspinatus and pectoral muscles utilizing the myoelectric biofeedback system with gain set at 7 with severe muscle guarding. The EMG data shown in Figure 2 demonstrates the patient’s minimal muscle contraction at baseline.
According to the Journal of Orthopedic and Sports Physical Therapy, the DASH outcome measure yields a sensitivity of 82% and 74% specificity.14 The DASH is a common outcome measure used due to its sensitivity, specificity, and carryover to upper-limb impairments. At initial evaluation, the patient scored an 80% disability. When asked about his injury and relation to sexual and social activities, the patient began to cry and stated his injuries significantly affected those areas of his life.
Other objective findings included full range of motion of the left upper limb, 115-cm edema measured around trunk at midaxillary line in sitting, and lack of arm swing contributing to gait abnormalities. Gait analysis also showed that patient ambulated with decreased step length on right likely due to lack of arm swing and trunk rotation. The patient is functionally independent with bed mobility, transfers, gait, and self-care. The patient is unable to lie on his back or close to right side due to pain.
Neurovascular testing included symptoms of tingling, cramping, pressure, and apprehension to touch. The physical therapist deferred sensation testing at time of initial examination due to increased pain with touch and patient apprehension.
The patient’s physical therapy diagnosis was shoulder amputation resulting in pain and impaired muscle function contributing to decrease function.
The International Classification of Functioning, Disability, and Health (ICF) is a classification of health and health-related domains that pertains to the functioning and disability of an individual.15 According to the ICF, the patient’s body structure and function primary impairment included right shoulder disarticulation with secondary impairments of PLP, chronic residual limb pain, muscle weakness, muscle control, and edema. The patient’s activity limitations included difficulty in sleeping, inability to write or perform heavy household chores, yard work, cook, or manage his own transportation needs. The patient’s participation limitations included recreational activities with his 15-year-old son, maximum difficulty with sexual activities with his wife, and decreased confidence interfering with his normal social activities.
The Guide to Physical Therapist Practice16 book is a tool utilized by physical therapists to describe physical therapy practice and define functional status of a patient. According to the guide, the patient’s treatment diagnosis is consistent with practice pattern 4J of impaired motor function, muscle performance, range of motion, gait locomotion, and balance associated with amputation.16 The patient’s therapy diagnosis is also consistent with the International Classification of Diseases, Ninth Revision (ICD-9) code 887.1 with traumatic amputation of arm and hand complete unilateral.16
PLAN OF CARE
Rehabilitation potential for the patient was determined to be good due to the patient’s high motivation, independent prior level of function, and active lifestyle. The plan of care included an 8-week treatment plan before prosthetic fitting followed by an additional 6-week plan for postprosthesis rehabilitation. The frequency was set at 1 to 2 times per week for 8 weeks due to the patient’s inability to independently drive to physical therapy sessions. Interventions focused on pain relief, decreased edema, decreased PLP, and improved muscular control to promote return to function. Physical therapy evaluations and goals were reviewed with the patient’s wife to promote family participation in his return to function. Short-term goals were to be achieved in 4 weeks and long-term goals in 8 weeks (see Table 1 for the specific short- and long-term goals).
IMPLEMENTATION OF INTERVENTION/REASSESSMENT
The patient presented to clinic with 9/10 pain in the supraclavicular region of the right residual limb. The wife reported that her husband would not allow her to touch him. Patient reported feeling more tenderness and increased soft tissue in midaxillary region since initial evaluation. Physical therapist measured circumferential measurement of 113 cm compared with initial evaluation of 115 cm. Mirror therapy treatment included sagittal plane movements of wrist extension, wrist flexion, and elbow flexion and elbow extension 2 × 40 in each direction (see Table 2 for biofeedback training of the infraspinatus and pectoral muscles on the right). Gain ratio was set at 7 for both muscles to contract individually; however, he was still unable to produce a sufficient contraction above baseline. In the supine position, the patient allowed the physical therapist light tapping and light massage to decrease edema and apprehension to touch.
The patient reported feeling better after previous physical therapy session with pain at 7/10 constant pressure and numbness and tingling on residual limb. Wife reported that she attempted to clean his wound but the husband still refused to let her touch him. Patient began to cry when wife discussed the impact his injury had on her life. Patient and wife were instructed to use a soft cloth such as silk to gently touch the residual limb and increase patient confidence with external stimuli. Biofeedback training consisted of short/quick, sustained, and gradual contraction of infraspinatus and pectoral muscles. The gain ratio was set at 7 for both muscle groups with evidence of stronger contraction for the pectoral muscles (see Table 2 for results of biofeedback training). Patient was able to see improvement of contraction on the computer screen. Patient immediately demonstrated a happier persona evidenced by his upright posture and joking with his translator. Other treatment techniques included mirror therapy sagittal plane exercises 2 × 40 in each direction and light touch in supine. Patient was still apprehensive about external stimuli from physical therapist.
The wife reported that her husband allowed her to gently stroke his right residual limb with her silk scarf. Patient reported feeling a 6/10 pain on the NPR scale along with pressure, numbness, and tingling. Patient was instructed to use Ace wrap around his upper trunk to decrease edema and promote tactile feedback for 1 hr twice a day. Patient stated that he had tried the prescribed mirror therapy at home and felt more confident about the treatment. Biofeedback training of the infraspinatus and pectoral muscles with gain set at 7 for both with short/quick contraction, sustained contraction for 3 seconds, and gradual contractions. Each of the types of contractions correlated with a different type of grip and position on the myoelectric arm (see Table 2 for biofeedback results for week 3). Other treatment techniques included supine external tactile feedback tapping, light scraping, and light retrograde massage. After gentle massage and cleaned residual limb, the patient’s midaxillary edema measurements were at 109 cm, 4 cm lateral to distal acromion. Patient demonstrated less apprehension with treatment.
Patient and wife reported feeling better about patient’s impairment. The wife reported that her husband was allowing her to lightly touch his residual limb. Wife was able to clean the scar and use a scarf for light tactile feedback. Patient reported only taking 2 pain medications per day as needed due to decreased pain to 5/10 according to the NPR scale. Patient reported wrapping arm every day for 2 hrs total. Patient reported that wrapping was uncomfortable but gave him a noticeable difference. The patient demonstrated marked decrease in edema measurement to 107 cm, 4 cm lateral to acromion. Patient demonstrated increased movement in sitting before treatment with ability to move his shoulder back and forth while individually contracting both muscles. Week 4 biofeedback training gain ratio for pectoral muscle set to 6 and set to 7 for infraspinatus muscle. Patient was able to adequately contract both muscles for short/quick contraction, sustained contraction, and gradual contraction (see Table 2 for EMG results of week 4). The patient was instructed to continue wrapping for 3 hrs a day and continue scarf tactile techniques with his wife each day.
The patient walked into clinic with his wife hand in hand. The patient reported pain at 4/10 with decreasing pressure but still numbness and tingling along surgical incision site on right lateral arm. Patient reported wrapping residual upper trunk with Ace wrap for 3 hrs a day with no increase in pain. Patient stated he was taking medication as needed but was not exceeding 2 pills per day. Patient reported for the first time being able to sleep through the night without pain. Edema measurement was 105.5 cm at midaxillary region 4 cm distal to lateral border of acromion. The treatment session included proprioceptive neuromuscular facilitation (PNF) scapular posterior depressions 3 × 12 to facilitate more range of motion, decrease pain, and increase muscular control. A study showed that patients with myofascial pain syndrome who received PNF showed statistically significant differences in the visual analog pain scale from 7.13 before treatment to 5.0 after treatment.17 By improving the efficiency of the neuromuscular control of muscles, normalizing muscle tone, and increasing the circulation of blood and tissue fluid, the study was able to adequately decrease patient pain and thus improve function.17 The treatment session also included supine light to moderate retrograde massage, tapping, scraping, and cleaning of scar. Research of stimulation-induced neural plasticity indicated that extensive behaviorally relevant stimulation of the affected part of the body led to an expansion of its representation zone and was shown to be positively linked to decreased PLP.18 As a result, the therapist used high-voltage electrical current to gait the pain and promote cortical reorganization. The patient reported discomfort and increased pain a couple hours after the H-wave treatment, but decreased pain the next day. Biofeedback training for infraspinatus and pectoral muscles with gain set at 5 for the pectoral and 6 for the infraspinatus muscles was also performed. Training included short/quick contraction, sustained contraction, and gradual contraction (see Table 3 for results of week 5 biofeedback training). Mirror therapy included wrist flexion, wrist extension, wrist radial deviation, wrist ulnar deviation, and elbow flexion and elbow extension 2 × 40 in each direction.
The patient reported a 4/10 pain according to the NPR scale with decreased numbness and tingling. Patient continued to wear Ace wrap 3 hrs a day. Edema measurement remained at 105.5 cm at midaxillary region. Treatments included scapular PNF posterior depression technique 3 × 10, light massage and tactile feedback, and high-voltage electrical stimulation to decrease neural sensation from residual limb pain and possible distal neuroma. Biofeedback training set pectorals at gain ratio 5 and infraspinatus at 6 with emphasis on short/quick contraction, sustained contraction, and gradual contraction (see Table 3 for results of biofeedback training). Mirror therapy included wrist flexion, wrist extension, wrist radial deviation, wrist ulnar deviation, and elbow flexion and elbow extension 2 × 40 in each direction.
The patient displayed significant gains in control of muscles evidenced by biofeedback therapy intervention with pectoral muscles gain set at 4 and infraspinatus at 5. Decrease in gain ratio demonstrated decreased amplitude, but more control of specific musculature (see Table 3 for results of biofeedback training). Patient expressed that he felt more confident with his wife touching his residual limb. Wife reported an improvement in their relationship since start of physical therapy. Patient was set up on high-voltage stimulation with intentions to activate the brachial plexus and decrease the sensation of pressure, numbness, and tingling. The patient still reported 4/10 pains according to the NPR scale. The patient demonstrated independence with mirror therapy and was able to demonstrate from memory in clinic, which indicated good follow-through with his home exercise program. Patient commented that he “was unable to show off for his wife” with the gain ratio set so low on the biofeedback system.
Treatment at the discharge date included biofeedback training with pectoral muscles at 4 and infraspinatus at 5 gain ratio with short/quick contraction, sustained contraction, and gradual increase contraction. Patient demonstrated more control and confidence with biofeedback training and decreased pain reported at 3/10 (see Table 3 for results of biofeedback training). Mirror therapy included wrist flexion, wrist extension, wrist radial deviation, wrist ulnar deviation, and elbow flexion and elbow extension 2 × 40 in each direction. The patient was comfortable with supine moderate retrograde massage with tapping and scraping. Midaxillary region edema measurements were 105.5 cm. Patient reported he was able to sleep on his back while leaning to right side of body with no pain or discomfort. The patient’s wife reported sexual activities had drastically increased since the beginning of the physical therapy sessions. Patient was scheduled to receive his prosthesis in 3 weeks. At week 8, the patient was discharged to a new physical therapist. The updated plan of care included pain reduction, muscular control, edema management, and mirror therapy to continue training with prosthesis.
The patient completed the initial 8-week course of treatment and demonstrated significant improvements in EMG biofeedback muscular control, DASH score, edema measurements, and PLP. The patient’s DASH score improved to 53% from an original 80%. The patient also showed a significant decrease in pain evidenced by 9/10 at initial evaluation decreased to 3/10 at discharge on the NPR scale. The patient also demonstrated improved muscular control with evidence of biofeedback training results. For short contraction, sustained contraction, and gradual contraction, the patient was able to reach 60 mV above baseline with sensitivity set at 4 for the pectoral major muscle and 5 for the infraspinatus muscle. At time of discharge, the patient met four of the six goals (Table 4). The patient did not meet the goals for the DASH outcome measure due to continued functional limitations in gardening, recreational activities, and driving. The circumferential edema measurement for the long-term goal was not achieved by 0.5 cm. The patient continued physical therapy for 6 weeks with a new physical therapist for prosthetic training.
According to a study by Subedi and Grossberg,19 it is estimated that there will be more than 3.6 million people with amputations by the year 2050. It is further suggested that more than 70% of these patients will experience some form of PLP.19 Although most studies have theorized the cause of PLP, there is no current research that reinforces the most beneficial treatment. However, many studies suggest a combination of multiple interventions to be beneficial, including mirror therapy, biofeedback training, and tactile stimulation. A mirror therapy protocol with wrist flexion, extension, radial deviation, ulnar deviation, pronation, supination, and shoulder flexion in combination with the biofeedback training demonstrated a 27% decrease in disability rating according to the DASH, and a pain rating decrease from a 9/10 to a 3/10. A study by Ramachandran and Altschuler20 hypothesized that the perception of the mirrored intact limb at the site of the pain could be controlled due to the neural memory that have stored sensory experiences of the missing limb.
The patient in this case report further strengthens the evidence found in previous studies in the potential benefits of mirror therapy, biofeedback, and tactile stimulation in treating a patient with residual limb and PLP. These interventions contributed to the patient’s improvements in pain, function, and the DASH outcome measures.
The limitations to this case report include a language barrier between Spanish-speaking patient and English-speaking therapist. With a recent and traumatic injury patient, the therapist may have benefited from more personal communication one-on-one with the patient instead of through an interpreter. The study was also limited by the insufficient amount of outcome measures. The study used the NPR scale and the DASH outcome measure to document improved function and perception of injury. An outcome measure to document confidence and self-efficacy would have been beneficial to document the patient’s improvement in self. The Assessment of Capacity for Myoelectric Control (ACMC) is an observational outcome measure that assesses the ability to control a myoelectric prosthetic hand with myoelectric control of appropriate muscle contraction.21 This outcome measure was not appropriate because the user must be certified. Another limitation included lack of sensory testing within the initial examination; as a result, the therapist was unable to objectively compare tactile feedback throughout the treatment sessions.
Despite complications of language barriers, limited outcome measures, and lack of sensory feedback during the examination, physical therapists should understand the benefits of combined mirror therapy, biofeedback training, and tactile stimulation in decreasing PLP and improving overall patient perception of self-improvement. Physical therapists should address muscular control through use of biofeedback for training purposes for prosthesis use and also for patient perception of movement and decreased fear of movement. Suggestions for future studies would be to include a larger sample size with 1 group of only biofeedback training, 1 group with only mirror therapy, and a combined group of biofeedback training and mirror therapy. Future studies could also utilize more reliable outcome measures to demonstrate improvement.
The author thanks Kayla Smith, PT, DSC, OCS, for mentoring the research and course of study.
1. Stark G. Shoulder disarticulation interface designs. Assoc Child Prosthet Orthot Clin
2010; 16: 26–33.
2. Highsmith J. Epidemiology and statistics associated with limb loss and limb deficiency. Prosthet Orthot
2009; 15: 37–43.
3. Dillingham TR, Pezzin LE, MacKenzie EJ. Limb amputation and limb deficiency: epidemiology and recent trends in the United States. South Med J
2002; 95: 875–883.
4. Phantom Limb Pain. WebMD. http://www.webmd.com/pain-management/guide/phantom-limb-pain
. Updated March 3, 2013. Accessed September 29, 2014.
5. Carlen PL, Wall PD, Nadvorna H, Steinbach T. Phantom limbs and related phenomena in recent traumatic amputations. Neurology
1978; 28: 211–217.
6. Nikolajsen L, Ilkjaer S, Krøner K, et al. The influence of preamputation pain on post amputation stump and phantom pain. Pain
1997; 72: 393–405.
7. Ramachandran VS, Rogers-Ramachandran D. Synesthesia in phantom limbs induced with mirrors. Proc Biol Sci
1996; 263: 377–386.
8. Chan B, Witt R, Charrow A. Mirror therapy for phantom limb pain. N Engl J Med
2007; 357: 2206–2207.
9. Sherman R, Sherman C. Physiological parameters that change when pain changes: approaches to unraveling the “cause-or-reaction” quandary. Bull Am Pain Society
1991; 1: 11–15.
10. Harden N, Houle T, Green S. Biofeedback in the treatment of phantom limb pain: a time-series analysis. Appl Psychophysiol Biofeedback
2005; 30: 83–93.
11. Basic Control Principles of the Otto Bock Myoelectric System Power Point. Otto Bock Health Care
. Available at http://www.ottobockus.com/prosthetics/info-for-new-amputees/prosthetics-101/myoelectric-prosthetics-101
. Accessed September 29, 2014.
12. Ostlie K, Franklin R. Assessing physical function in adult acquired major upper-limb amputees by combining the Disabilities of the Arm, Shoulder and Hand (DASH) Outcome Questionnaire and clinical examination. Arch Phys Med Rehabil
2011; 92: 1636–1645.
13. Van Der Laan K. Numeric Pain Rating Scale. Rehab Measures. January 17, 2013. http://www.rehabmeasures.org/Lists/RehabMeasures/DispForm.aspx?ID=891
14. Franchignoni F, Vercelli S. Minimal Clinically Important Difference of the Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH) and its Shortened Version (QuickDASH). J Orthop Sports Phys Ther
2014; 44: 30–39.
15. Bernis-Dougherty A. Practice matters: what is ICF? PT in Motion 2009; http://www.apta.org/PTinMotion/2009/2/Feature/PracticeMatters/ICF
16. Massey B, Bohmert J, Levine S, et al. Impaired Motor Function, Muscle Performance, Range of Motion, Gait, Locomotion, and Balance Associate with Amputation. Guide to Physical Therapist Practice 3.0
. Alexandria: American Physical Therapy Association; 2014.
17. Lee J, Park S, Na S. The effect of proprioceptive neuromuscular facilitation therapy of pain and function. J Phys Ther Sci
2013; 25: 713–716.
18. Sumitani M, Yozu A, Tomioka T, et al. Using the intact hand for objective assessment of phantom hand-perception. Eur J Pain
2010; 14: 261–265.
19. Subedi B, Grossberg G. Phantom limb pain: mechanisms and treatment approaches. Pain Res Treat
2011; 8646025. Published online 2011 August 14.
20. Ramachandran VS, Altschuler EL. The use of visual feedback, in particular mirror visual feedback, in restoring brain function. Brain
2009; 132: 1693–1710.
21. Lindner H. The assessment of capacity for myoelectric control psychometric evidence and comparison with upper limb prosthetic outcome measures. J Rehabil Med
2013; 41: 467–474.