Seeking sufficient and appropriate care during the first year after spinal cord injury: a qualitative study.

STUDY DESIGN: Longitudinal qualitative study, based on a constructivist grounded theory and transformative approach. OBJECTIVES: This study investigated experiences of individuals with spinal cord injury (SCI) while navigating rehabilitation, resources for recovery, and community reintegration during the first year after injury. SETTING: An acute inpatient rehabilitation facility in the Midwest United States. METHODS: In-depth, semi-structured interviews were conducted with 20 individuals with newly-acquired SCI. Interviews were conducted approximately every other month for one year, beginning at acute inpatient rehabilitation. Data were analyzed and interpreted using a constructivist grounded theory approach and transformative paradigm, which examines power and social structures within and across institutions and gives voice to people at risk for marginalization. RESULTS: Participants experienced variable post-injury trajectories, with an average of four transitions within and across healthcare institutions in the first three months. Half of the cohort was discharged to a skilled nursing facility (SNF). Emergent themes included discharge (un)readiness; length of stay uncertainty and insurance impacts; challenges choosing a SNF including time-sensitive decisions; and early cessation of therapy in the SNF. Participants experienced resource navigation challenges such as communication/information access barriers and contending with many concerns at once. CONCLUSIONS: The experiences of this cohort reveal significant challenges to attaining sufficient and appropriate rehabilitation. Acute inpatient rehabilitation is a critical aspect of recovery, but does not ensure sufficient intervention for maximization of functional skills and community reintegration. Innovative rehabilitation models need to be developed for positive impacts on successful transition to independent living in the community.

Corticospinal inhibition investigated in relation to upper extremity motor function in cervical spinal cord injury.

OBJECTIVE: Corticospinal inhibitory mechanisms are relevant to functional recovery but remain poorly understood after spinal cord injury (SCI). Post-injury characteristics of contralateral silent period (CSP), a measure of corticospinal inhibition evaluated using transcranial magnetic stimulation (TMS), is inconsistent in literature. We envisioned that investigating CSP across muscles with varying degrees of weakness may be a reasonable approach to resolve inconsistencies and elucidate the relevance of corticospinal inhibition for upper extremity function following SCI. METHODS: We studied 27 adults with chronic C1-C8 SCI (age 48.8 ± 16.1 years, 3 females) and 16 able-bodied participants (age 33.2 ± 11.8 years, 9 females). CSP characteristics were assessed across biceps (muscle power = 3-5) and triceps (muscle power = 1-3) representing stronger and weaker muscles, respectively. We assessed functional abilities using the Capabilities of the Upper Extremity Test (CUE-T). RESULTS: Participants with chronic SCI had prolonged CSPs for biceps but delayed and diminished CSPs for triceps compared to able-bodied participants. Early-onset CSPs for biceps and longer, deeper CSPs for triceps correlated with better CUE-T scores. CONCLUSIONS: Corticospinal inhibition is pronounced for stronger biceps but diminished for weaker triceps muscle in SCI indicating innervation relative to the level of injury matters in the study of CSP. SIGNIFICANCE: Nevertheless, corticospinal inhibition or CSP holds relevance for upper extremity function following SCI.

Definitions of recovery and reintegration across the first year: A qualitative study of perspectives of persons with spinal cord injury and caregivers.

STUDY DESIGN: Longitudinal, qualitative cohort study. OBJECTIVES: To understand how people with newly acquired spinal cord injury (PWS) and their support person (SP) define recovery and successful community reintegration (CR) across the first 12 months post-injury (mpi) and their satisfaction with the rate of recovery and reintegration experienced. SETTING: Academic and Veterans hospitals in Midwest USA. METHODS: In-depth, semi-structured interviews were conducted in two cohorts of PWS and SP during the initial inpatient rehabilitation stay, at 6 mpi, and at 12 mpi. Recordings were transcribed; four authors independently undertook line-by-line coding. The team discussed codes to reach consensus and synthesize into broader themes within the International Classification of Function, Disability, and Health and Transformative frameworks. RESULTS: Data are reported on 23 PWS and 21 SP. PWS and SP are similar in defining recovery as gaining motor function and achieving independence. However, SP more frequently define recovery in terms of maintaining positivity and emotional recovery. At 12 mpi both groups shift to define recovery according to progress. Social roles, being active, and employment are persistent themes of how PWS and SP define successful CR. However, SP also frequently define successful CR as reestablishing identity and emotional adjustment. Veterans with SCI less frequently defined successful CR as employment. CONCLUSIONS: This study is the first to reveal how PWS and SP define recovery and reintegration during the first 12 mpi. Given decreasing lengths of stay, this information can be used to tailor rehabilitation strategies during the critical first year of injury to optimize recovery.

Clinical Outcomes of "Paralyzed" Nerve Transfer for Treating Spinal Cord Injury: A Proof of Concept in a Human Model.

Functional electrical stimulation (FES) is an option to restore function in individuals after high cervical spinal cord injury (SCI) who have limited available options for tendon or nerve transfer. To be considered for FES implantation, patients must possess upper motor neuron (UMN) type denervation in potential recipient muscles, which can be confirmed by response to surface electrical stimulation during clinical evaluation. Lower motor neuron (LMN) denervated muscles will not respond to electrical stimulation and, therefore, are unavailable for use in an FES system. Previous animal studies have demonstrated that a "paralyzed" nerve transfer of a UMN-denervated motor branch to an LMN-denervated motor branch can restore electrical excitability in the recipient. In this study, we report the indications, surgical technique, and successful outcome (restoration of M3 elbow flexion) after the first "paralyzed" nerve transfer in a human patient.

Preoperative evaluation of nerve transfer recipients after spinal cord injury using stimulated manual muscle testing.

Nerve transfer after spinal cord injury has become increasingly popular. Accurate preoperative identification of lower motor neuron involvement in potential recipient nerves is critical. Electrodiagnostic testing has been shown to correlate with intraoperative findings; however, it is time-consuming, costly and may not be readily available. Stimulated manual muscle testing is an alternative diagnostic approach. It is inexpensive and easily done by the surgeon or therapist in the office; however, correlation with intraoperative stimulation has not been reported. A retrospective review was conducted for patients who underwent nerve transfer for tetraplegia with recorded preoperative stimulated manual muscle testing and intraoperative stimulation results. Nine patients including 37 nerve transfers were included. Of the 37 nerve transfers, 36 were accurately graded preoperatively by stimulated manual muscle testing. Stimulated manual muscle testing had a sensitivity of 89%, specificity of 100%, positive predictive value of 100% and a negative predictive value of 97%. This study supports stimulated manual muscle testing for preoperative distinction between upper versus lower motor neuron injuries.Level of evidence: IV.

Grasp and Release Test for Tetraplegic Hand Assessment: an update of the Grasp and Release Test.

The Grasp and Release Test (GRT) was originally developed to measure effectiveness of an implanted neuroprosthesis in people with tetraplegia. Its ease of use and lack of floor and ceiling effects culminated in recommendations for inclusion in a battery of tests to measure outcome following upper limb reconstructive surgery. However, the length of time taken to administer the GRT in a clinical setting, lack of instructions of accepted grasp patterns in the upper limb reconstructive surgery population and scoring procedures lead to differences in reporting outcomes using this measure. In order to ensure clinical utility for the upper limb reconstructive surgery population, revisions of the original test instructions have been made and are reported in this article. Further testing of the psychometric properties of the new measure are currently underway.

Can the electrically stimulated manual muscle test differentiate upper from lower motor neuron injury in persons with acute SCI?

OBJECTIVE: To determine if the motor response on the stimulated manual muscle test (SMMT) in muscles with a grade 0 motor score on the manual muscle test (MMT) can differentiate lower motor neuron (LMN) from upper motor neuron (UMN) injury based on the presence of spontaneous activity (SA) with needle EMG. DESIGN: Prospective Study. PARTICIPANTS/METHODS: Twenty-one subjects with acute traumatic cervical SCI. METHODS: An upper extremity International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) evaluation was completed on all subjects. A needle EMG and an electrically stimulated manual muscle test (SMMT) were completed on all key upper extremity muscles with a MMT motor score of zero. RESULTS: The MMT, SMMT and Needle EMG were done on 77 muscles. The SMMT motor score was 0 on 10 muscles and >1 on 67 muscles. The needle EMG identified spontaneous activity (SA) in 55/77 muscles. Seventy percent (7/10) of the muscles with MMT and SMMT motor score of zero demonstrated SA on EMG. Seventy-two percent (48/67) of the muscles with MMT motor score = 0 and SMMT motor score ≥1 demonstrated SA on EMG. CONCLUSION: In our study, 70% of the muscles with a SMMT motor response of zero and 72% of the muscles with a SMMT motor response greater than or equal to one demonstrated SA on EMG. The use of the SMMT as a clinical measure to differentiate LMN from UMN integrity may be limited when applied.

Safety and efficacy of transcranial direct current stimulation in upper extremity rehabilitation after tetraplegia: protocol of a multicenter randomized, clinical trial.

STUDY DESIGN: A multisite, randomized, controlled, double-blinded phase I/II clinical trial. OBJECTIVE: The purpose of this clinical trial is to evaluate the safety, feasibility and efficacy of pairing noninvasive transcranial direct current stimulation (tDCS) with rehabilitation to promote paretic upper extremity recovery and functional independence in persons living with chronic cervical spinal cord injury (SCI). SETTING: Four-site trial conducted across Cleveland Clinic, Louis Stokes Veterans Affairs Medical Center of Cleveland and MetroHealth Rehabilitation Rehabilitation Institute of Ohio, and Kessler Foundation of New Jersey. METHODS: Forty-four adults (age ≥18 years) with tetraplegia following cervical SCI that occurred ≥1-year ago will participate. Participants will be randomly assigned to receive anodal tDCS or sham tDCS given in combination with upper extremity rehabilitation for 15 sessions each over 3-5 weeks. Assessments will be made twice at baseline separated by at least a 3-week interval, once at end-of-intervention, and once at 3-month follow-up. PRIMARY OUTCOME MEASURE(S): Primary outcome measure is upper extremity motor impairment assessed using the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) scale. Functional abilities will be assessed using Capabilities of Upper Extremity-Test (CUE-T), while functional independence and participation restrictions will be evaluated using the self-care domain of Spinal Cord Independent Measure (SCIM), and Canadian Occupational Performance Measure (COPM). SECONDARY OUTCOME MEASURES: Treatment-associated change in corticospinal excitability and output will also be studied using transcranial magnetic stimulation (TMS) and safety (reports of adverse events) and feasibility (attrition, adherence etc.) will also be evaluated. TRIAL REGISTRATION: ClincalTrials.gov identifier NCT03892746. This clinical trial is being performed at four sites within the United States: Cleveland Clinic (lead site), Louis Stokes Cleveland Veterans Affairs Medical Center (VAMC) and MetroHealth Rehabilitation Institute in Ohio, and Kessler Foundation in New Jersey. The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office.

A Rare Case of Spontaneous Arachnoid Cyst Rupture Presenting as Right Hemiplegia and Expressive Aphasia in a Pediatric Patient.

This study examines an 11-year-old boy with a known history of a large previously asymptomatic arachnoid cyst (AC) presenting with acute onset of right facial droop, hemiplegia, and expressive aphasia. Shortly after arrival to the emergency department, the patient exhibited complete resolution of right-sided hemiplegia but developed headache and had persistent word-finding difficulties. Prior to symptom onset while in class at school, there was an absence of reported jerking movements, headache, photophobia, fever, or trauma. At the time of neurology consultation, the physical exam showed mildly delayed cognitive processing but was otherwise unremarkable. The patient underwent MRI scanning of the brain, which revealed left convexity subdural hematohygroma and perirolandic cortex edema resulting from ruptured left frontoparietal AC. He was evaluated by neurosurgery and managed expectantly. He recovered uneventfully and was discharged two days after presentation remaining asymptomatic on subsequent outpatient visits. The family express concerns regarding increased anxiety and mild memory loss since hospitalization.

International Spinal Cord Injury Physical Therapy-Occupational Therapy Basic Data Set (Version 1.2).

STUDY DESIGN: Expert workgroup consensus, focused literature review, and vetting via feedback from international presentations and spinal cord professional membership groups. OBJECTIVES: Develop and refine a basic dataset to enable standardized documentation of physical therapy (PT) and occupational therapy (OT) interventions delivered in a controlled clinical trial intended to improve voluntary motor function. SETTING: International Expert Working Group. METHODS: An international working group with expertise in spinal cord injury, PT, OT, and measurement developed a draft of the International Spinal Cord Injury (ISCI) Physical Therapy-Occupational Therapy (PT-OT) Basic Data Set (BDS). Emphasis was placed on efficiency and practicality of use. The BDS was iteratively refined based on applicable literature, and feedback collected from presentations at the 2017 and 2019 International Spinal Cord Society meetings. RESULTS: The ISCI PT-OT BDS contains seven broad categories of interventions: bed/seated mobility, standing activities, walking/stairs, gross motor upper extremity, fine motor upper extremity, strength training, and endurance training. The first five categories are classified as activity-directed and the last two as impairment-directed interventions. Time spent on interventions per category is recorded in 15-min intervals. CONCLUSIONS: The ISCI PT-OT BDS enables standardized documentation of PT-OT activity-directed or impairment-directed interventions. The ISCI PT-OT BDS is a documentation tool to facilitate evaluation of the influence of rehabilitation therapies on motor function in clinical trials of biologic or pharmacologic agents or rehabilitation technologies that are delivered in the clinical setting.

A Primary Care Provider's Guide to Social Justice, the Right to Care, and the Barriers to Access After Spinal Cord Injury.

People living with spinal cord injury (SCI) face numerous barriers to primary care. This article identifies these barriers as social justice issues to emphasize their significance and the inequality of primary care received by people with SCI. Primary care providers have a responsibility to provide equal and accessible care to all patients and to remediate any obstacles to care. Understanding the well-documented barriers of competence, physical, policy and procedural, communication, and attitudes impacting primary care for people with SCI will bring much-needed awareness and opportunity for meaningful change. This article is a call to action for social justice within primary care and provides helpful recommendations for removing and addressing barriers. Better health care outcomes for people with SCI are possible if primary care physicians and providers become social justice advocates for their patients with SCI.

Risk-benefit value of upper extremity function by an implanted electrical stimulation device targeting chronic cervical spinal cord injury.

Study design: A cross-sectional stated-preference survey using direct-assessment questions. Objective: To determine the relative value placed on different outcomes to be used in a pivotal trial for the upper extremity configuration of the Networked Neuroprosthesis (NNP) as well as the tolerance of the expected adverse event profile. Setting: Academic medical center in the United States. Methods: Distribution of an online survey to adults living with tetraplegia; extent of agreement with each question/statement was obtaining using a 1-7 Likert scale. Results: There were 8 statements about potential benefits in arm/hand function; for all statements, more than 70% of participants rated the functions as "1-very important" to regain. There were variable degrees of concern related to risks that could occur during the 30-day post-surgical period and increasing degrees of concern related to risks that could occur in the first 5 years, potentially due to the device, based on the increasing degree of invasiveness of the intervention required to address the event. When analysing the results based on all degrees of interest, more than 64% of responders were interested in getting the NNP with a success rate threshold as low as 50% regardless of time post-injury. Chi-squared analyses revealed some associations between responses and sex, injury level, and injury duration; however, none of these were statistically significant upon post-hoc analysis. Conclusion: Data here indicate that people with tetraplegia are highly interested in a range of arm/hand functions and are tolerant of expected risks that may be associated with implanted neuroprosthetics. Sponsorship: The Institute for Functional Restoration funded this project through a sub-contract to K.D. Anderson from a larger Special Projects Award (grant number FP0020773) from the Craig H. Neilsen Foundation.

Neuromodulation for Functional Electrical Stimulation.

This article describes the application of neuromodulation in different ways to motor recovery, to replace lost function, or to improve function of organ systems for those who have experienced spinal cord injury or stroke. Multiple devices have been developed and are currently available for use whereas others are still in the experimental stage. Multiple uses of neuromodulation are described.

Advanced Assessment of the Upper Limb in Tetraplegia: A Three-Tiered Approach to Characterizing Paralysis.

Background: More than half of all individuals who sustain a spinal cord injury (SCI) experience some degree of impairment in the upper limb. Functional use of the arm and hand is of paramount importance to these individuals. Fortunately, the number of clinical trials and advanced interventions targeting upper limb function are increasing, generating optimism for improved recovery and restoration after SCI. New interventions for restoring function and improving recovery require more detailed examination of the motor capacities of the upper limb. Objectives: The purpose of this article is to introduce a three-tiered approach to evaluating motor function, with specific attention to the characteristics of weak and fully paralyzed muscles during acute rehabilitation. The three tiers include (1) evaluation of voluntary strength via manual muscle testing, (2) evaluation of lower motor neuron integrity in upper motor neuron-paralyzed muscles using surface electrical stimulation, and (3) evaluation of latent motor responses in paralyzed muscles that exhibit a strong response to electrical stimulation, using surface electromyographic recording electrodes. These characteristics contribute important information that can be utilized to mitigate potential secondary conditions such as contractures and identify effective interventions such as activity-based interventions or reconstructive procedures. Our goal is to encourage frontline clinicians - occupational and physical therapists who are experts in muscle assessment - to consider a more in-depth analysis of paralysis after SCI. Conclusion: Given the rapid advancements in SCI research and clinical interventions, it is critical that methods of evaluation and classification evolve. The success or failure of these interventions may depend on the specific characteristics identified in our three-tiered assessment. Without this assessment, the physiological starting point for each individual is unknown, adding significant variability in the outcomes of these interventions.

Comparison of Responsiveness and Minimal Clinically Important Difference of the Capabilities of Upper Extremity Test (CUE-T) and the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP).

Background: The Capabilities of Upper Extremity Test (CUE-T) and the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) were both developed to detect change in upper extremity (UE) function in persons with tetraplegia. Objective: To compare the responsiveness and minimal clinically important difference (MCID) of the CUE-T and the quantitative prehension (QtP) scale of the GRASSP. Methods: Subjects included 69 persons with tetraplegia: 60 with acute and 9 with chronic injuries. Subjects were assessed twice 3 months apart using the CUE-T, QtP-GRASSP, and upper extremity motor scores (UEMS). Subjects rated their impression of change in overall and right/left UE function from -7 to +7. The standardized response mean (SRM) was determined for acute subjects. MCID was estimated using a small subjective change (2-3 points) and change in UEMS. Results: Subjects were 41.9 ± 18.1 years old, neurological levels C1-C7; 25 were motor complete. For acute subjects, the SRMs for total/side CUE-T scores were 1.07/0.96, and for the QtP-GRASSP they were 0.88/0.78. MCIDs based on subjective change for total/side CUE-T scores were 11.7/6.1 points and for QtP-GRASSP were 6.4/3.0 points. Based on change in UEMS, MCIDs for total/side were 11.9/6.3 points for CUE-T and 6.0/3.3 points for QtP-GRASSP. Some subjects had changes in the CUE-T due to its arm items that were not seen with the QtP-GRASSP. Conclusion: Both the CUE-T and QtP-GRASSP are responsive to change in persons with acute cervical spinal cord injury with large SRMs. The CUE-T detects some changes in UE function not seen with the QtP-GRASSP.

Evolution of Neuroprosthetic Approaches to Restoration of Upper Extremity Function in Spinal Cord Injury.

Background: Spinal cord injury (SCI) occurring at the cervical levels can result in significantly impaired arm and hand function. People with cervical-level SCI desire improved use of their arms and hands, anticipating that regained function will result in improved independence and ultimately improved quality of life. Neuroprostheses provide the most promising method for significant gain in hand and arm function for persons with cervical-level SCI. Neuroprostheses utilize small electrical currents to activate peripheral motor nerves, resulting in controlled contraction of paralyzed muscles. Methods: A myoelectrically-controlled neuroprosthesis was evaluated in 15 arms in 13 individuals with cervical-level SCI. All individuals had motor level C5 or C6 tetraplegia. Results: This study demonstrates that an implanted neuroprosthesis utilizing myoelectric signal (MES)-controlled stimulation allows considerable flexibility in the control algorithms that can be utilized for a variety of arm and hand functions. Improved active range of motion, grip strength, and the ability to pick up and release objects were improved in all arms tested. Adverse events were few and were consistent with the experience with similar active implantable devices. Conclusion: For individuals with cervical SCI who are highly motivated, implanted neuroprostheses provide the opportunity to gain arm and hand function that cannot be gained through the use of orthotics or surgical intervention alone. Upper extremity neuroprostheses have been shown to provide increased function and independence for persons with cervical-level SCI.

Considerations and recommendations for selection and utilization of upper extremity clinical outcome assessments in human spinal cord injury trials.

STUDY DESIGN: This is a focused review article. OBJECTIVES: This review presents important features of clinical outcomes assessments (COAs) in human spinal cord injury research. Considerations for COAs by trial phase and International Classification of Functioning, Disability and Health are presented as well as strengths and recommendations for upper extremity COAs for research. Clinical trial tools and designs to address recruitment challenges are identified. METHODS: The methods include a summary of topics discussed during a two-day workshop, conceptual discussion of upper extremity COAs and additional focused literature review. RESULTS: COAs must be appropriate to trial phase and particularly in mid-late-phase trials, should reflect recovery vs. compensation, as well as being clinically meaningful. The impact and extent of upper vs. lower motoneuron disease should be considered, as this may affect how an individual may respond to a given therapeutic. For trials with broad inclusion criteria, the content of COAs should cover all severities and levels of SCI. Specific measures to assess upper extremity function as well as more comprehensive COAs are under development. In addition to appropriate use of COAs, methods to increase recruitment, such as adaptive trial designs and prognostic modeling to prospectively stratify heterogeneous populations into appropriate cohorts should be considered. CONCLUSIONS: With an increasing number of clinical trials focusing on improving upper extremity function, it is essential to consider a range of factors when choosing a COA. SPONSORS: Craig H. Neilsen Foundation, Spinal Cord Outcomes Partnership Endeavor.

Factors associated with upper extremity contractures after cervical spinal cord injury: A pilot study.

OBJECTIVE: To examine the prevalence of joint contractures in the upper limb and association with voluntary strength, innervation status, functional status, and demographics in a convenience sample of individuals with cervical spinal cord injury to inform future prospective studies. DESIGN: Cross-sectional convenience sampled pilot study. SETTING: Department of Veterans Affairs Research Laboratory. PARTICIPANTS: Thirty-eight participants with cervical level spinal cord injury. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Contractures were measured with goniometric passive range of motion. Every joint in the upper extremity was evaluated bilaterally. Muscle strength was measured with manual muscle testing. Innervation status was determined clinically with surface electrical stimulation. Functional independence was measured with the Spinal Cord Independence Measure III (SCIM-III). RESULTS: Every participant tested had multiple joints with contractures and, on average, participants were unable to achieve the normative values of passive movement in 52% of the joints tested. Contractures were most common in the shoulder and hand. There was a weak negative relationship between percentage of contractures and time post-injury and a moderate positive relationship between percentage of contractures and age. There was a strong negative correlation between SCIM-III score and percentage of contractures. CONCLUSIONS: Joint contractures were noted in over half of the joints tested. These joint contractures were associated with decreased functional ability as measured by the SCIM-III. This highlights the need the need for detailed evaluation of the arm and hand early after injury as well as continued monitoring of joint characteristics throughout the life course of the individual with tetraplegia.

Voluntary activation of biceps-to-triceps and deltoid-to-triceps transfers in quadriplegia.

The biceps or the posterior deltoid can be transferred to improve elbow extension function for many individuals with C5 or C6 quadriplegia. Maximum strength after elbow reconstruction is variable; the patient's ability to voluntarily activate the transferred muscle to extend the elbow may contribute to the variability. We compared voluntary activation during maximum isometric elbow extension following biceps transfer (n = 5) and deltoid transfer (n = 6) in three functional postures. Voluntary activation was computed as the elbow extension moment generated during maximum voluntary effort divided by the moment generated with full activation, which was estimated via electrical stimulation. Voluntary activation was on average 96% after biceps transfer and not affected by posture. Individuals with deltoid transfer demonstrated deficits in voluntary activation, which differed by posture (80% in horizontal plane, 69% in overhead reach, and 70% in weight-relief), suggesting inadequate motor re-education after deltoid transfer. Overall, individuals with a biceps transfer better activated their transferred muscle than those with a deltoid transfer. This difference in neural control augmented the greater force-generating capacity of the biceps leading to increased elbow extension strength after biceps transfer (average 9.37 N-m across postures) relative to deltoid transfer (average 2.76 N-m across postures) in our study cohort.

Posture-Dependent Corticomotor Excitability Differs Between the Transferred Biceps in Individuals With Tetraplegia and the Biceps of Nonimpaired Individuals.

BACKGROUND: Following biceps transfer to enable elbow extension in individuals with tetraplegia, motor re-education may be facilitated by greater corticomotor excitability. Arm posture modulates corticomotor excitability of the nonimpaired biceps. If arm posture also modulates excitability of the transferred biceps, posture may aid in motor re-education. OBJECTIVE: Our objective was to determine whether multi-joint arm posture affects corticomotor excitability of the transferred biceps similar to the nonimpaired biceps. We also aimed to determine whether corticomotor excitability of the transferred biceps is related to elbow extension strength and muscle length. METHODS: Corticomotor excitability was assessed in 7 arms of individuals with tetraplegia and biceps transfer using transcranial magnetic stimulation and compared to biceps excitability of nonimpaired individuals. Single-pulse transcranial magnetic stimulation was delivered to the motor cortex with the arm in functional postures at rest. Motor-evoked potential amplitude was recorded via surface electromyography. Elbow moment was recorded during maximum isometric extension trials, and muscle length was estimated using a biomechanical model. RESULTS: Arm posture modulated corticomotor excitability of the transferred biceps differently than the nonimpaired biceps. Elbow extension strength was positively related and muscle length was unrelated, respectively, to motor-evoked potential amplitude across the arms with biceps transfer. CONCLUSIONS: Corticomotor excitability of the transferred biceps is modulated by arm posture and may contribute to strength outcomes after tendon transfer. Future work should determine whether modulating corticomotor excitability via posture promotes motor re-education during the rehabilitative period following surgery.