Initial factors predicting functional performance in patients with traumatic tetraplegia

Handgrip Strength Cutoff Points for Functional Independence and Wheelchair Ability in Men With Spinal Cord Injury

Objectives

To determine optimal handgrip strength (HGS) cutoff points for greater functional independence and wheelchair skills in men with spinal cord injury (SCI), and to establish predictive equations for functional independence and wheelchair ability in men with SCI, based on demographic characteristics, HGS, and functionality.

Methods

In this cross-sectional study conducted at a rehabilitation hospital, 54 men with SCI were recruited and stratified into high and low paraplegia groups. All participants performed a maximum HGS test to determine cutoff points for the Spinal Cord Independence Measure (SCIM-III) and Adapted Manual Wheelchair Circuit (AMWC). The primary outcomes were the SCIM-III, AMWC, and HGS. Demographic characteristics obtained from participants' electronic medical records were the secondary outcomes, used as predictor variables of functional independence.

Results

The SCIM-III scale, performance score, and 3-minute overground wheeling test presented significant regression equations (R = 0.45, R = 0.69, and R = 0.72). The HGS showed a cutoff point of 102.5 kilogram force (kgf) to achieve a score of 70 on the SCIM-III and a 3-minute overground wheeling distance of 270 m. The HGS cutoff point to obtain a performance score of 23.7 seconds was 93.0 kgf.

Conclusion

The HGS was a significant predictor for the SCIM-III score, AMWC performance score, and 3-minute overground wheeling test. Three significant predictive equations were established based on HGS. The cutoff points could be adopted as parameters for optimal functional independence and wheelchair skills.

Influence of Relative Strength on Functional Independence of Patients With Spinal Cord Injury

OBJECTIVE

To investigate the influence of strength values and fat mass on functional independence of men with different spinal cord injury (SCI) levels.

DESIGN

Cross-sectional study.

SETTING

Hospital network.

PARTICIPANTS

Men with SCI (N=45).

INTERVENTIONS

Subjects were assessed in functional independence scales, a 1 repetition maximum (1RM) test, and body composition to detect absolute and relative strength: 1RM divided by body mass (BM) and lean body mass (LBM), respectively.

MAIN OUTCOME MEASURES

Stepwise multiple regression analysis was used to verify the influence of predictors on functional independence (FIM and Spinal Cord Independence Measure [SCIM] scale and subscales). Receiver operating characteristic curves were created to identify cutoff points of strength for functional independence.

RESULTS

The best models for FIM total, FIM mobility, and SCIM total used 1RM as the best predictor (adjusted R²=.75, .67, and .65, respectively; P<.05). Relative strength (1RM/LBM) was the best predictor for SCIM mobility (adjusted R²=.62, P<.05). A FIM score of 69 has a 1RM cutoff point of 50.1kg, and a FIM score of 76 has cutoff points of .73 for 1RM/BM and .91 for 1RM/LBM. A SCIM score of 68 has cutoff points for 1RM, 1RM/BM, and 1RM/LBM of 50.1kg, .77, and .92, respectively.

CONCLUSIONS

Cutoff points of relative strength should be used as determinant variables for independence, health, or sports performance. This study may contribute to more adequate guidance of physical activity during a rehabilitation program and after discharge.

Measurement, nature, and implications of skeletal muscle strength in patients with neurological disorders

Muscle strength is frequently impaired in patients with neurological disorders. Numerous instrumented and non-instrumented options exist for measuring the strength of such patients. Such measurements are useful for clarifying patient status and documenting changes over time. Moreover the measurements are often informative of present or future function among a variety of diagnostic groups. Measurements of muscle strength are an essential component of the neurological evaluation and provide information of substantial importance to clinical care.

Evidence of subclinical brain influence in clinically complete spinal cord injury: discomplete SCI

Previous studies of the neurocontrol of movement in spinal cord injury (SCI) subjects revealed that even those without volitional movement may retain some degree of preservation of distal brain influence. We previously defined a discomplete lesion as one which is clinically complete but which is accompanied by neurophysiological evidence of residual brain influence on spinal cord function below the lesion. In order to document the nature and extent of such neurocontrol, we recorded surface EMGs from multiple muscle groups to study patterns of motor unit activity in response to tendon vibration, activation of muscles below the lesion by reinforcement maneuvers above the lesion and by voluntary suppression of plantar withdrawal reflexes. We analyzed data from this brain motor control assessment (BMCA) procedure in order to describe the frequency of occurrence and characteristics of residual control in discomplete SCI subjects, comparing with findings in (clinically and neurophysiologically) complete and in (clinically and neurophysiologically) incomplete SCI subjects. From a group of 139 SCI subjects seen for management of spasticity, 88 had clinically complete lesions. Of these, 74 (84%) were discomplete as defined by responses to the above maneuvers. The selection of management and intervention strategies, whether physiological, pharmacological, behavioral or surgical, should give consideration to the high likelihood that clinically complete subjects may be neurophysiologically incomplete.