Biomedical subjects

JoAnne K Gronley

Publications and source records attributed to JoAnne K Gronley.

4 recordsLinked to original sources

PubMed2006

A comparison of shoulder joint forces during ambulation with crutches versus a walker in persons with incomplete spinal cord injury.

OBJECTIVE: To compare 3-dimensional (3D) shoulder joint reaction forces and stride characteristics during bilateral forearm crutches and front-wheeled walker ambulation in persons with incomplete spinal cord injury (SCI). DESIGN: Cross-sectional cohort study. SETTING: Biomechanics laboratory. PARTICIPANTS: Fourteen adult volunteers with incomplete SCI recruited from outpatient rehabilitation hospital services. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Peak force, rate of loading, and force-time integral were compared for each component of the net 3D shoulder joint reaction force during ambulation with crutches and a walker. Stride characteristics were also compared between assistive device conditions. RESULTS: The largest weight-bearing force was superiorly directed, followed by the posterior force. The superior joint force demonstrated a significantly higher peak and rate of loading during crutch walking (48.9N and 311.6N/s, respectively, vs 45.3N and 199.8N/s, respectively). The largest non-weight-bearing force was inferiorly directed with a significantly greater peak occurring during crutch ambulation (43.2N vs 23.6N during walker gait). Walking velocity and cadence were similar; however, stride length was significantly greater during crutch walking (62% vs 58% of normal). CONCLUSIONS: Shoulder joint forces during assisted ambulation were large. Crutch use increased the superior force but did not increase walking velocity.

Adult↗

PubMed2005

Effect of fore-aft seat position on shoulder demands during wheelchair propulsion: part 1. A kinetic analysis.

BACKGROUND/OBJECTIVE: The highly repetitive and weight-bearing nature of wheelchair (WC) propulsion has been associated with shoulder pain among persons with spinal cord injury (SCI). Manipulation of WC seat position is believed to reduce the overall demand of WC propulsion. The objective of this investigation was to document the effect of fore-aft seat position on shoulder joint kinetics. METHODS: Thirteen men with complete motor paraplegia propelled a test WC in 2 fore-aft seat positions during free, fast, and graded conditions. The seat-anterior position aligned the glenohumeral joint with the wheel axle and the seat-posterior position moved the glenohumeral joint 8 cm posteriorly. The right wheel of the test chair was instrumented to measure forces applied to the pushrim. An inverse dynamics algorithm was applied to calculate shoulder joint forces, external moments, and powers. RESULTS: For all test conditions, the superior component of the shoulder joint resultant force was significantly lower in the seat-posterior position. During graded propulsion, the posterior component of the shoulder joint force was significantly higher with the seat posterior. Peak shoulder joint moments and power were similar during free and fast propulsion. During graded propulsion, the seat-posterior position displayed increased internal rotation moment, decreased sagittal plane power absorption, and increased transverse plane power generation. CONCLUSIONS: This investigation provides objective support that a posterior seat position reduces the superior component of the shoulder joint resultant force. Consequently, this intervention potentially diminishes the risk for impingement of subacromial structures.

Acceleration↗

PubMed2004

The supine hip extensor manual muscle test: a reliability and validity study.

OBJECTIVES: To define the relative hip extensor muscle strengths values identified by the 4 grades obtained with a supine manual muscle test (MMT) and to compare these values with those indicated by the traditional prone test. DESIGN: Comparison of 4 manual supine strength grades with isometric hip extension joint torque; kappa statistic-determined interrater reliability, and analyses of variance identified between grade differences in torque. SETTING: Pathokinesiology laboratory. PARTICIPANTS: Adult volunteers recruited from local community and outpatient clinics. Reliability testing: 16 adults with postpolio (31 limbs). Validity testing (2 groups): 18 subjects without pathology (18 limbs), and 26 people with clinical signs of hip extensor weakness (51 limbs). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Supine hip extensor manual muscle grade and isometric hip extension torque. RESULTS: Reliability testing showed excellent agreement (82%). Subjects with pathology had significant differences in mean torque (P<.01) for the assigned grade 5 (176 Nm), grade 4 (103 Nm), grade 3 (67 Nm), and grade 2 (19 Nm). Healthy adults showed significant differences between grade 5 (212 Nm) and grade 4 (120 Nm) in mean torque (P<.05). CONCLUSIONS: The supine MMT is a reliable and valid method with which to assess hip extension strength.

Activities of Daily Living↗

PubMed2003

Toe walking: muscular demands at the ankle and knee.

OBJECTIVE: To compare the relationship between electromyographic activity and internal moment in heel-toe and toe walking. DESIGN: Simultaneous recording of stride characteristics and kinematic, kinetic, and intramuscular electromyographic data; paired t tests identified significant between-condition differences. SETTING: Gait laboratory. PARTICIPANTS: Ten able-bodied subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Kinematic, moment, power, and electromyographic variables (ankle, knee). RESULTS: Compared with heel-toe walking, toe walking showed greater plantarflexion during stance (P<.001), higher plantarflexor moments (peak, mean) during loading response (P<.001) and midstance (P<.001), lower mean plantarflexor moments during terminal stance (P=.002), premature soleus (P=.001) and gastrocnemius (P<.001) activity, and higher levels of mean soleus and gastrocnemius activity during stance. During toe walking, the peak internal knee extensor moment was lower in midstance (P=.002), and power absorption was reduced in loading response; however, vastus intermedius electromyographic activity was not reduced. CONCLUSIONS: During toe walking, terminal stance soleus and gastrocnemius activity was greater, despite a lower mean internal plantarflexor moment. The dichotomy between internal moments and muscle effort (ie, electromyographic activity) was consistent with the reduction in force-generation capacity of the calf muscles when the ankle was in a plantarflexed position.

Adult↗